Ingredients
1/4 cup extra-virgin olive oil
1 medium onion, minced
4 garlic cloves, minced
1 pinch crushed red pepper flakes
1 28 ounce can peeled tomatoes, puréed in a food processor
Kosher salt
3 large fresh basil sprigs
12 ounces bucatini or spaghetti
2 tablespoons cubed unsalted butter
1/4 cup finely grated Parmesan or Pecorino
