French Onion Soup

French onion soup features deeply caramelized, golden onions that create a rich and intensely flavorful base, topped with crusty bread and melted cheese. The slow cooking of the onions brings out their natural sweetness, making every spoonful comforting and satisfying. Easy to prepare with simple ingredients, it’s a classic soup that feels indulgent without any fuss.

Love More Soup Recipes? Try My Italian Sausage Tortellini Soup or this Spanish Potato Soup With Chorizo next.

Why You’ll Love This Recipe

Caramelized onions and melted cheese make this soup rich, comforting, and almost foolproof to prepare. It looks elegant on the table, yet requires minimal effort, making you feel like a gourmet cook without the stress. The irresistible aroma fills the kitchen and draws everyone in, turning any meal into a crowd-pleasing event.

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Ingredient List

Soup stuff:

• ½ cup butter (salted, unsalted, whatever you have)
• 2 tablespoons olive oil (or vegetable oil if that’s all you got)
• 4 cups onions, sliced however you want
• 5 cups beef broth from a box (don’t get fancy)
• 2 tablespoons sherry (cooking wine from the grocery store works)
• 1 teaspoon dried thyme (fresh is fine too)
• Salt and pepper to taste

Cheese pile:

• 4 pieces bread (stale French bread is perfect, regular bread works)
• 4 slices provolone cheese
• 2 slices Swiss cheese, chopped up
• Some Parmesan cheese, grated (the stuff in the green can is fine)

When you’re missing stuff:

• No sherry? Skip it entirely. Use white wine if you have it open. Use cooking wine. Use nothing at all.
• Wrong cheese? Mozzarella works great. Sharp cheddar is good. Whatever’s in your fridge that melts.
• Vegetarian friends coming? Use vegetable broth instead of beef broth.
• No French bread? Regular sandwich bread, sourdough, whatever. Just use something sturdy.

Why These Ingredients Work

Butter and oil together stops the burning. I learned this after ruining dinner three times in a row and my husband suggesting we just order pizza forever. The butter tastes good, the oil has a higher smoke point. Together they’re magic for not burning onions.

Four cups of onions looks completely stupid when you start. Like way too many onions. But they cook down to basically nothing and get sweet like candy. I use yellow onions mostly because they’re cheap and always available. Sweet onions work great too but cost more. Don’t use red onions unless you like things sharp and weird.

Beef broth makes it taste like actual soup instead of onion water. I tried making my own broth once. Took all day and tasted exactly the same as the box stuff. Now I buy boxes of broth and keep them in the pantry. Get the low-sodium kind so you can control the salt yourself.

Sherry makes it taste expensive and fancy. My mom always used cooking sherry from the grocery store, the stuff that tastes terrible if you drink it but works perfect in food. If you have real sherry, great. If you don’t, the cooking wine section has what you need for like three bucks.

Thyme makes it smell French or something. I don’t know the science but it works. Dried thyme from the spice aisle is perfectly fine. Fresh thyme is great if you grow herbs or shop at fancy stores, but don’t make a special trip.

The cheese situation is where people get weird and complicated. Provolone melts smooth and doesn’t get stringy. Swiss cheese tastes nutty and good. Parmesan gets crispy and brown on top. That’s literally all I know about cheese science and it’s enough.

Essential Tools and Equipment

You need a big pot. I use my Dutch oven because it’s heavy and doesn’t burn stuff as easily. Any big pot works though. Stockpot, large saucepan, whatever you have that fits four cups of onions plus five cups of liquid.

Sharp knife is important because cutting onions with a dull knife makes you cry harder and takes forever. Also you’re more likely to cut yourself with a dull knife trying to force it through onions. Sharpen your knives or buy a cheap sharp one just for onions.

Four bowls that won’t explode in the oven. This is super important. Regular bowls crack under the broiler and make a huge mess. Oven-safe bowls, ceramic ramekins, little casserole dishes all work. I learned this lesson the hard way when I destroyed two of my nice bowls.

Cookie sheet to put the bowls on. Makes it easier to move everything in and out of the oven without burning yourself or dropping hot soup everywhere.

How To Make French Onion Soup

Step 1: Melt Stuff

Put the butter and oil in your big pot. Turn heat to medium. Wait till it starts bubbling a little bit. Don’t let it get brown or smoke, just melted and bubbly. This takes like two minutes.

Step 2: Cook Onions

Cook the onions in butter and oil, stirring every few minutes until they shrink down and turn soft and translucent, about 15–20 minutes. Adjust the heat as needed to prevent browning too quickly or to speed things up.

Step 3: Add Liquid and Seasonings

Add the beef broth, sherry, thyme, salt, and pepper to the softened onions, then bring to a gentle simmer. Let it cook for 30 minutes so the flavors meld while you prep the bread and cheese.

Step 4: Heat Your Broiler

About five minutes before the soup finishes, preheat your broiler and position the oven rack about 6 inches from the element to brown the cheese evenly without burning.

Step 5: Taste and Adjust

After 30 minutes of simmering, taste your soup. Add more salt if it tastes bland. Add more pepper if you like it spicier. Add more thyme if you want it more herby. This is your soup, make it taste how you like it.

Step 6: Fill Bowls and Add Toppings

Ladle the soup into four oven-safe bowls and top each with a slice of bread. Layer provolone, Swiss, and Parmesan on the bread generously for a cheesy finish.

Step 7: Broil Until Perfect

Place the bowls on a baking sheet and broil 2–3 minutes until the cheese is melted and golden brown, watching closely to avoid burning. Let cool for a minute before serving, as the cheese will be very hot.

You Must Know

Don’t rush the onions. This is where most people mess up. Keep the heat at medium or even medium-low. Stir them regularly but don’t stand there stirring constantly. They need time to soften and release their sweetness. If they start browning before they’re soft, your heat is too high.

My biggest secret: Use day-old bread that’s a little stale. Fresh soft bread gets mushy and falls apart in the soup. Stale bread holds together better and doesn’t get soggy. Carol taught me this and it completely changed how my soup turned out.

Pro Tips & Cooking Hacks

Make extra onions. If you’re already crying and cutting onions, cut up a few extra and freeze them. Next time you want to make this soup, you can skip the crying part and just dump frozen onions straight into the pot.

The cognac trick. If you want to get fancy, add a splash of cognac or brandy with the sherry. Makes it taste more expensive. Don’t buy expensive cognac for cooking – the cheap stuff works fine.

Don’t cover the pot when cooking onions. They release water as they cook and if you cover them, they steam instead of caramelizing. You want the water to evaporate so they get sweet, not soggy.

Smart shortcuts. Buy pre-sliced onions from the grocery store if you hate cutting onions or don’t have time. They’re more expensive but sometimes convenience wins.

Frozen onion hack. Frozen onions work great in this soup. They break down faster when cooking and get really soft and sweet. Plus no crying.

Flavor Variations & Suggestions

More caramelized version: Cook the onions for 45 minutes to an hour instead of 15-20 minutes. Keep stirring occasionally and let them get deep brown and jammy. Takes longer but gives you that super-sweet caramelized onion flavor.

Extra herbs: Use fresh thyme instead of dried if you have it. Throw in a bay leaf while the soup simmers, just remember to take it out before serving. Some people add rosemary but I think it’s too strong.

Wine version: Use dry white wine instead of sherry. About the same amount, maybe a little more. Makes it taste lighter and more acidic. Good if you don’t like the sweetness of sherry.

Beer version: My brother-in-law uses beer instead of sherry. Like half a bottle of whatever he’s drinking. Makes it taste completely different but still good.

Mushroom addition: Cook sliced mushrooms with the onions. Adds more flavor and makes it more filling. Use button mushrooms or cremini, whatever’s cheap.

Spicy version: Add some red pepper flakes with the thyme. Not a lot, just a pinch. Gives it a little kick without overpowering the onion flavor.

Vegetarian version: Use vegetable broth or mushroom broth instead of beef broth. Still tastes great, just different. Some vegetable broths are really salty so taste before you add extra salt.

Make-Ahead Options

Day before: Make the entire soup base the day before you want to serve it. Let it cool completely and stick it in the fridge. The flavors actually get better overnight. When you’re ready to eat, reheat the soup gently and then do the bread and cheese part.

Week before: The soup base freezes perfectly for months. Make a huge batch when onions are cheap and freeze it in containers. Thaw overnight in the fridge and reheat when you want soup.

Morning of: Make the soup in the morning before work. Leave it in the pot and reheat it when you get home. Add the bread and cheese right before serving.

Meal prep version: Make the soup and portion it into containers. When you want some, heat a portion in the microwave, pour it into an oven-safe bowl, add bread and cheese, and broil. Single serving French onion soup in five minutes.

Party planning: If you’re making this for a crowd, make the soup base ahead and keep it warm in a slow cooker. Set up a station with bowls, bread, and cheese so people can assemble their own and stick them under the broiler.

Recipe Notes & Baker’s Tips

Onion cutting technique: Cut onions from top to bottom, not in rings. They hold together better when cooking and don’t fall apart into weird pieces. Also they cook more evenly this way.

Broth quality matters: Don’t buy the absolute cheapest broth but don’t go crazy either. The stuff in boxes is usually better than the cans. Low-sodium gives you more control over salt levels.

Oven-safe bowl test: If you’re not sure if your bowls are oven-safe, check the bottom. Most have symbols or words that tell you. When in doubt, use ceramic ramekins or small casserole dishes.

Cheese grating tip: Grate your own Parmesan if you have time. It melts better than the pre-grated stuff and tastes fresher. But honestly, the green can stuff works fine too.

Storage containers: The soup base keeps in the fridge for about a week. Any longer and it starts tasting weird. Freeze it if you want to keep it longer.

Reheating advice: Reheat leftover soup gently on the stove, not in the microwave. Microwaving makes the onions taste weird and changes the texture.

Serving Suggestions

What goes with it: This soup is pretty filling on its own, especially with all that cheese and bread. If you want sides, a simple green salad works great. Something light and acidic cuts through all the rich cheese.

Bread for dipping: Keep extra bread around for dipping in the soup. Crusty French bread, sourdough, whatever you like. People always want more bread.

When to serve it: Perfect for cold nights when you want something warm and comforting. Great for Sunday dinner when you have time to let it simmer. Good for impressing guests without actually doing much work.

Portion sizes: This makes four generous portions. My teenage boys can eat a whole bowl each plus seconds. Adults usually have one bowl and are satisfied. Kids might need a smaller portion depending on their age.

How to Store Your French Onion Soup

Refrigerator storage: The soup base without bread and cheese keeps in the fridge for 4-5 days. Store it in containers with tight lids. The onions might settle to the bottom but just stir when you reheat.

Freezer storage: Just the soup part freezes perfectly for up to 6 months. I use freezer bags or containers. Thaw overnight in the fridge before reheating. Don’t freeze it with the bread and cheese already added.

Reheating instructions: Reheat leftover soup slowly on the stove over medium-low heat. Stir occasionally so it heats evenly. Don’t rush it or the onions can get weird and mushy.

Already assembled leftovers: If you have leftover soup with the bread and cheese already in it, reheat in a 300-degree oven for about 10 minutes. This keeps the cheese from getting rubbery like it does in the microwave.

Portion control: I sometimes freeze the soup in single-serving containers. Then I can thaw just what I need for lunch or a quick dinner. Perfect for when only one person wants soup.

Allergy Information

Contains: Dairy from butter and cheese, gluten from the bread

Dairy-free modifications: Use olive oil instead of butter. Skip the cheese or use dairy-free cheese alternatives. Some of the new plant-based cheeses actually melt pretty well.

Gluten-free options: Serve without bread, or use gluten-free bread if you have it. The soup itself doesn’t have any gluten. You could also put it over rice or just eat it as is.

Vegetarian friendly: Just swap the beef broth for vegetable broth or mushroom broth. Everything else is already vegetarian. The flavor is different but still really good.

Low-sodium version: Use low-sodium broth and taste before adding any salt. You might not need to add any extra salt at all.

Questions I Get Asked A Lot

Can I use different types of onions?

Yeah, but they all taste different. Yellow onions are my go-to because they’re cheap and available everywhere. Sweet onions like Vidalia are great but more expensive. White onions work fine. Red onions are too sharp and make the soup taste weird, so I avoid those.

Why isn’t my cheese browning under the broiler?

Move your oven rack closer to the broiler element. Most people have it too far away. It should be about 6 inches from the heat source. Also make sure your broiler is actually hot before you put the soup in.

Can I use chicken broth instead of beef broth?

Sure. It tastes different – lighter and less rich – but still good. I prefer beef broth for the deeper flavor but chicken broth works fine if that’s what you have.

My soup tastes bland. What should I add?

More salt, probably. Taste it after everything has simmered together for the full 30 minutes, then add salt gradually until it tastes good to you. You might also need more pepper or thyme.

💬 Made this soup? Tell me about it in the comments! I want to hear if you used different cheese, burnt it like I did the first few times, or if your kids actually ate vegetables without complaining.