Step 1: Prepare the Shrimp

1. Preheat oven to 400°F (200°C).
2. Pat shrimp dry with paper towels and season with salt, black pepper, and red pepper flakes.

Step 2: Make the Garlic Sauce

1. In a large skillet over medium heat, melt butter and add minced garlic. Sauté until fragrant, about 1 minute.
2. Pour in the white wine (if using) and let it simmer for 1-2 minutes to reduce.
3. Add heavy cream and Parmesan cheese, stirring until the sauce thickens slightly.
4. Stir in lemon juice and remove from heat.

Step 3: Assemble the Gratin

1. Arrange shrimp in a single layer in a baking dish.
2. Pour garlic cream sauce over shrimp, ensuring even coverage.
3. Sprinkle shredded mozzarella over the top.

Step 4: Add the Crispy Topping

1. In a small bowl, mix panko breadcrumbs with olive oil and chopped parsley.
2. Evenly distribute breadcrumb mixture over the shrimp and cheese layer.

Step 5: Bake

1. Place the baking dish in the preheated oven and bake for 12-15 minutes, or until shrimp turn pink and the top is golden brown.
2. If needed, broil for an additional 1-2 minutes to achieve a crispy topping.

Step 6: Serve

1. Remove from the oven and let it rest for a few minutes before serving.
2. Garnish with additional parsley and serve warm.