Meanwhile, in another large heavy-bottomed skillet, melt 2 tablespoons butter and olive oil over medium-low heat. Add the garlic. Saute for 1 minute. Be careful, the garlic burns easily! Add the shrimp, salt and pepper, red pepper flakes, and saute until the shrimp have just turned pink (about 5 minutes), stirring often. Remove shrimp from pan. Add white wine, lemon juice, lemon zest, 2 tablespoons butter and parsley. Bring to a low boil. Return shrimp to saute pan.