1 cup grated parmesan cheese, preferably Parmigiano-Reggiano (divided)
5 cloves fresh garlic, finely minced, or to taste
Crushed red pepper flakes, to taste
2 cups fresh Italian (flat-leaf) parsley, finely minced (about 1 cup chopped)
Sea salt or kosher salt
Bring a large pot of salted water to a vigorous, rolling boil. Cook pasta until
Drain well and put into a warm serving dish with the soft butter in it;
toss pasta until coated, then add most of the cheese and gently toss again. Keep
warm in oven.
Heat the olive oil in a saucepan over medium heat. Add the minced garlic and
red pepper flakes and cook just until the garlic turns light brown; pull pan off
the heat. (Do not rush by cooking at a higher heat; this will burn the garlic and
cause it to taste bitter.)
Add the minced parsley and a generous pinch of salt and mix with a spoon until
it resembles the texture of pesto.
Immediately pour over the warm pasta and toss
well to distribute the sauce evenly.