The test kitchen prefers the hearty strands of egg-enriched fettuccine (usually sold in 12-ounce boxes). We found that you need to salt the water used to cook the pasta and vegetables quite heavily to make sure they emerge nicely seasoned.
2 tablespoons unsalted butter
1 small onion, chopped fine
8 ounces white mushrooms, quartered
Table salt and ground black pepper
2 garlic cloves, minced
1 (14.5-ounce) can diced tomatoes, drained
1 cup heavy cream
12 ounces egg-enriched dried fettuccine (see note)
1 pound asparagus, tough ends snapped off, spears cut diagonally into 1-inch pieces
1 medium zucchini cut into 1/2-inch dice
1 cup frozen peas
1/2 cup grated Parmesan cheese, plus extra for serving
1 1/2 tablespoons fresh lemon juice
1/4 cup thinly sliced fresh basil leaves
Bring 4 quarts water to boil in large pot for cooking pasta. Meanwhile, melt butter in large skillet over medium heat until foaming. Add onion, mushrooms, 1/2 teaspoon salt, and 1/2 teaspoon pepper and cook until soft and browned, about 8 minutes. Add garlic and cook until fragrant, about 1 minute. Stir in tomatoes and cream, increase heat to high, bring to boil, and remove pan from heat.
While sauce cooks, add 2 tablespoons salt and pasta to boiling water and cook until just beginning to soften, about 6 minutes. Add asparagus to pot and cook for 1 minute. Add zucchini and cook for 2 minutes. Add peas and cook until pasta is al dente, about 1 minute.
Drain pasta and vegetables and return to pot. Toss in cream sauce, cheese, lemon juice, and basil and season with salt and pepper. Serve, passing extra cheese at table.
from Cook's Illustrated e-mail