In a large skillet over medium heat, melt ½ tablespoon of butter. Add the garlic and sauté until fragrant, about 1 minute.

Add the lobster and crab meat, cooking for 2 to 3 minutes, then remove from heat and set aside.

In a large bowl, combine the cooked seafood with the cream cheese, ½ cup shredded mozzarella, and season with salt and pepper. Mix well until fully combined.

Cook the jumbo pasta shells according to the package instructions. Drain and let them cool slightly before filling with the seafood mixture.

In the same skillet, melt the remaining butter over medium heat. Add the flour and cook for about 1 minute, stirring constantly.

Gradually add the heavy cream, whisking to combine.

Stir in the grated Parmesan cheese and remaining shredded mozzarella, continuing to stir until the sauce becomes smooth and creamy.

Preheat the oven to 375 degrees Fahrenheit (190 degrees Celsius).

Spread a thin layer of the cheese sauce on the bottom of a baking dish.

Stuff the cooled pasta shells with the seafood filling and place them in the baking dish.

Pour the remaining cheese sauce over the stuffed shells.

Cover the dish with aluminum foil and bake for 20 minutes.

Remove the foil and bake for an additional 10 minutes, or until the top is bubbly and golden.

Let the dish cool slightly before serving. Garnish with extra Parmesan or fresh herbs for added flavor.