Place the shrimp in a bowl and toss with 1 tsp kosher salt, 1/2 tsp black pepper, minced garlic, and 1 tbsp lemon juice. Let sit 5 minutes to marinate briefly.

Heat pan

Heat a large skillet over medium-high heat until hot (about 2 minutes). Add 1 tbsp olive oil and swirl to coat the bottom.

Sear shrimp

Add the shrimp to the pan in a single layer without crowding. Cook undisturbed 1.5 to 2 minutes until the underside turns pink and develops light golden edges.

Flip and finish

Flip the shrimp and add 1 tbsp unsalted butter and 1/4 tsp red pepper flakes to the pan. Cook another 1 to 1.5 minutes until shrimp are opaque throughout and firm to the touch (internal temperature ~120–130°F / 49–54°C for medium-rare to medium). Spoon the butter and pan juices over the shrimp as they finish.

Finish and garnish

Remove the pan from heat. Stir in chopped parsley and adjust seasoning to taste with more salt or lemon juice if desired. Transfer shrimp to the serving dish.

Optional finishing

Serve with lemon wedges and a sprinkle of grated Parmesan if using. Use the lemon to brighten flavors right before eating.