Meanwhile, in another large, heavy-bottomed pan, melt the butter and olive oil over medium-low heat. Add the garlic. Saute for 1 minute. Be careful, the garlic burns easily! Add the shrimp, 1 teaspoon of salt, and the pepper and saute until the shrimp have just turned pink, about 5 minutes, stirring often. Remove from the heat, add the parsley, lemon zest, lemon juice, lemon slices, and red pepper flakes. *I served up my kids first and then tossed in the red pepper flakes since it does add a lot of heat. Toss to combine.