1. Bring a large pot of water to a rolling boil. Add a generous pinch of salt — the water should taste pleasantly salty. Cook the fettuccine until just al dente per package instructions. Before draining, scoop out ½ cup of the starchy pasta water and set it aside in a small cup. Drain the pasta and toss with a small drizzle of olive oil to prevent sticking. Set aside.

2. Use the still-hot pasta water (or bring a small separate pan of water to a boil) and blanch the asparagus pieces for exactly 2 minutes. Add the peas and blanch for 1 more minute. Drain immediately and set aside. Blanching locks in the bright green color and keeps both vegetables crisp-tender rather than olive-colored and soft.

3. Heat olive oil in a large skillet over medium heat. Add the minced garlic and cook for 1 minute, stirring constantly, until fragrant but not browned at all. Add the chopped fresh spinach with a small pinch of salt. Cook for 2–3 minutes, stirring continuously, until the spinach wilts down completely. The volume drops dramatically — this is exactly right.

4. Transfer the wilted spinach and garlic to a blender. Add the heavy cream, grated Parmesan, salt, pepper, lemon juice, and the pinch of nutmeg if using. Blend on high for 30–45 seconds until completely smooth and the sauce looks vibrantly, deeply green. Return the sauce to the skillet over the lowest heat setting. If it looks thicker than you want, stir in a splash of the reserved pasta water to loosen it to a pourable consistency.

5. Add the blanched asparagus and peas into the warm sauce and stir gently. Add the drained fettuccine and toss with tongs for 1–2 minutes until every ribbon of pasta picks up a full coat of green sauce and the vegetables distribute evenly throughout. Add more pasta water a tablespoon at a time if the sauce thickens too much. Divide into bowls immediately. Top each portion with fresh chopped basil, toasted pine nuts, a generous amount of freshly grated Parmesan, and a little lemon zest. Serve right away.