Step 1: Preheat the oven

1. Preheat your oven to 400°F (200°C).

Step 2: Prepare the shrimp

1. Pat the shrimp dry with paper towels and season with salt and black pepper.
2. Heat 2 tablespoons of butter in a skillet over medium heat. Add the shrimp and cook for 1-2 minutes per side, until just pink and slightly undercooked. Remove the shrimp from the skillet and set aside.

Step 3: Make the garlic cream sauce

1. In the same skillet, add the remaining 1 tablespoon of butter and the minced garlic. Sauté for 1 minute until fragrant.
2. Stir in the heavy cream and white wine (if using), and simmer for 2-3 minutes until slightly thickened.
3. Remove from heat and stir in the Parmesan cheese, lemon juice, and parsley.

Step 4: Assemble the gratin

1. Arrange the shrimp in a single layer in a small baking dish or ovenproof skillet. Pour the garlic cream sauce evenly over the shrimp.
2. Sprinkle the mozzarella cheese over the top, followed by the breadcrumbs.

Step 5: Bake the gratin

1. Place the dish in the preheated oven and bake for 10-12 minutes, or until the cheese is melted and golden brown. For an extra crispy topping, broil for 1-2 minutes at the end.

Step 6: Garnish and serve

1. Garnish with additional parsley and serve immediately with crusty bread, rice, or a side salad.