Meanwhile, melt butter in a large skillet over medium-high heat. Add garlic and sauté for 1 minute. Add broth, red pepper flakes and pepper and bring to a simmer.
Add shrimp and sauté until slightly pink (2 to 4 minutes depending upon their size). Stir in lemon juice and zest.
Serve shrimp and sauce over pasta and top with parmesan cheese and fresh parsley.