In a large skillet, melt butter with olive oil. Add garlic and sauté until fragrant, about 1 minute. Add wine or broth, salt, red pepper flakes and plenty of black pepper and bring to a simmer. Let wine reduce by half (about 2 minutes).
Add shrimp and sauté until they just turn pink, 2 to 4 minutes depending upon their size. Stir in the parsley and lemon juice and serve over pasta or accompanied by crusty bread.