Pan

Peel the shrimp, leaving the tails on if desired. Using a sharp knife, cut down the back of each shrimp to butterfly it open, being careful not to cut all the way through. Devein if necessary.

Heat a skillet over medium-high heat and add 1 tablespoon of butter. Once melted, place the butterflied shrimp cut-side down in the pan.

Use a grill press or spatula to press the shrimp down firmly to ensure a good sear and create a nice crust. Cook for 1-2 minutes.

Squeeze the juice of half a lemon over the shrimp in the pan. Cover with a lid and cook for another 1-2 minutes, or until the shrimp are pink and cooked through.

While the shrimp cook, prepare the sauce. In a small bowl, combine the 4 tablespoons of melted butter, Old Bay seasoning, and chopped fresh parsley. Stir to combine.

Remove the cooked shrimp from the pan and arrange them on a serving plate. Pour the butter sauce over the top and serve immediately.