Step 1

Bring a large pot of salted water to a rolling boil.

Step 2

Meanwhile, in a 10-inch skillet over medium-high heat, heat the olive oil until it shimmers. Add the mushrooms and a pinch of salt and saute, stirring occasionally, until pale brown, about 5 minutes. Add the spring onions or scallions and cook, stirring occasionally, until warmed through, about 1 minute. Stir in the crushed red pepper flakes, if using, and remove the pan from the heat.

Step 3

Add the fettuccine to the boiling water and cook approximately halfway, until malleable but still quite firm, 4 to 5 minutes. Add the broccoli, snap or snow peas, and asparagus. Cook until the fettuccine is al dente – or done to your liking – and the vegetables are bright green and tender, 4 to 6 minutes. Stir in the frozen peas, and let them cook for 20 seconds. Reserve 1/4 cup of pasta water. Drain the pasta and vegetables, but do not shake them to dry further. Immediately transfer them back to the pot.

Step 4

Return the skillet with the mushrooms and spring onions to medium heat. Stir in the cream or half-and-half, followed by the cheese, letting it melt. Add the mushroom and cream mixture to the pasta and vegetables, along with the cherry tomatoes and reserved pasta water, and cook, stirring, until the sauce just barely coats everything. Taste, and season with more salt, if desired. If you like the pasta saucier, add more cream and/or cheese. Divide among 4 plates or shallow bowls, top with basil and black pepper, and serve.