Shrimp pasta recipe

8 oz spaghetti or your favorite pasta 1 lb large shrimp, peeled and deveined 3 tablespoons unsalted butter 4 cloves garlic, minced 1/4 teaspoon red pepper flakes (optional, for a bit of heat) 1/2 cup chicken broth or white wine Juice of 1 lemon Zest of 1 lemon 1/4 cup grated Parmesan cheese 1/4 cup chopped fresh parsley