Step 1: Pat the Shrimp Completely Dry: If using frozen shrimp, thaw completely (overnight in the fridge or 15 minutes in cold water). Remove the shells and devein if needed. Lay the shrimp out on paper towels and pat the top and bottom until no moisture remains. This step is critical — wet shrimp will not sear, they will steam, and the butter will become watery instead of rich.
Step 2: Sizzle the Garlic in Butter: Heat a skillet over medium heat. Add 2 tablespoons of butter. When the butter melts and starts to bubble, add the minced garlic (and red pepper flakes if using). Sauté for 30 to 60 seconds until the garlic is fragrant and just beginning to turn a pale gold. Do not let the garlic brown — browned garlic is bitter and will ruin the sauce.
Step 3: Sear the Shrimp: Arrange the dried shrimp in the skillet in a single layer. Sprinkle with salt and black pepper. Let them sear for 2 minutes without moving them — you want the bottom to turn pink and opaque and the edges to curl slightly. Don't stir or flip too early. The sear develops flavor.
Step 4: Flip, Add Butter and Parsley: After 2 minutes, flip each shrimp. Add the remaining 1 tablespoon of butter and the chopped parsley. The butter melts into the pan and combines with the garlic to create a rich sauce. Cook for another 1 to 2 minutes until the shrimp are fully opaque, pink all over, and curved into a "C" shape.
Step 5: Add Lemon Juice and Serve: Turn off the heat. Squeeze the juice of half a lemon over the shrimp — the lemon juice hits the hot butter and creates a slight emulsion that thickens and brightens the sauce. Plate immediately, spoon the garlic butter sauce from the pan over the shrimp, and serve with lemon wedges on the side and extra parsley for color.