Cook the pasta in a pot of salted boiling water until 2 minutes from al dente, then add in the peas. When the pasta is cooked, drain both into a strainer.
salt, for cooking pasta, 4 ounce cavatappi or other short pasta, ½ cup frozen peas
Using the same pot, combine the butter, cream, and nutmeg over medium-low heat until slightly thickened.
1 tablespoon unsalted butter, 1 tablespoon heavy cream, 1 pinch nutmeg
Add the pasta and peas back to the pot and continue to stir over medium-low heat until the pasta is well-coated.
Off the heat, stir in the Parmesan cheese, salt and pepper to taste, and serve immediately with extra Parmesan cheese, as desired.
½ ounce grated Parmesan cheese, plus more for topping