Step 1

Bring a large pot of salted water to a boil over medium-high heat. Cook pasta until al dente according to package directions.

Step 2

As the pasta boils, slice asparagus stems into ¼-inch-thick pieces; leave asparagus tips whole.

Step 3

Melt butter in a large skillet over medium-high heat. Add asparagus, peas, scallions and red-pepper flakes. Cook until vegetables are bright green and just tender (but not soft or mushy), 2 to 4 minutes. Stir in garlic and cook 1 minute more. Season with the salt and ¼ teaspoon black pepper; pour mixture into a large serving bowl.

Step 4

To the same skillet, add the heavy cream, ½ cup grated Parmesan and ¼ teaspoon pepper. Simmer until reduced and thick, about 2 to 3 minutes. Return vegetables to the skillet and toss with the sauce to reheat.

Step 5

When the pasta is done, reserve ½ cup pasta water, then drain well.

Step 6

Immediately put the hot pasta in the same bowl you used for the vegetables and toss with remaining ¼ cup grated Parmesan, lemon zest and mint. Add vegetable-cream mixture and the juice of half a lemon, and toss well. If the mixture looks thick, add a little pasta water to loosen it; it should be saucy. Taste and season generously with salt, pepper and more lemon juice as needed; it should taste bright and lively. Serve, topping each bowl with more Parmesan, mint and a drizzle of olive oil.