1. Prepare Ingredients:
- Gather all your ingredients. Peel and devein the shrimp if not already done; pat them thoroughly dry with paper towels. Finely mince the garlic. Chop the parsley (divide for sauce and garnish). Juice the lemon. Cut the cold butter into 4 pieces.
2. Sear the Shrimp:
- Heat the 1 ½ tablespoons of olive oil in a large, heavy skillet over high heat until the oil just begins to smoke.
- Carefully place the patted-dry shrimp in a single, even layer on the bottom of the hot pan.
- Cook for 1 minute without stirring to allow a nice sear to develop on the first side.
- Season the shrimp lightly with salt. Continue to cook and stir (or flip) until the shrimp just begin to turn pink and curl, about 1 minute more. Do not overcook at this stage.
3. Add Aromatics & Build Sauce Base:
- Add the finely minced garlic and the red pepper flakes to the skillet with the shrimp.
- Cook and stir constantly for about 1 minute, until the garlic is very fragrant. Be careful not to burn the garlic.
- Stir in the fresh lemon juice and the caper brine.
- Add one piece (1/4 of the total 2 tbsp) of the cold butter and about half of the chopped fresh parsley to the skillet. Cook, stirring or swirling the pan, until this first piece of butter has melted, about 1 minute.
4. Finish Sauce with Remaining Butter:
- Reduce the heat under the skillet to low.
- Add the remaining 3 pieces of cold butter to the pan, one piece at a time.
- Cook and stir (or swirl the pan) constantly until all the butter has melted and emulsified into the sauce, creating a smooth, slightly thickened, and glossy sauce. This should take 2 to 3 minutes. The shrimp will finish cooking gently during this time and become pink and opaque.
5. Adjust Sauce and Serve:
- Using a slotted spoon, remove the cooked shrimp from the skillet and transfer them to a bowl or serving platter to prevent overcooking.
- Continue to cook the butter sauce in the skillet over low heat for about 2 minutes more, allowing it to reduce very slightly. If the sauce seems too thick for your liking, stir in the 1 teaspoon of water (or more, a tiny bit at a time) until it reaches your desired consistency.
- Taste the sauce and season with additional salt if needed.
- To serve, arrange the cooked shrimp on plates. Spoon the hot garlic-lemon butter pan sauce generously over the shrimp.
- Garnish with the remaining fresh chopped parsley. Enjoy immediately