In a large skillet, melt 2 tablespoons of butter over medium heat. Add 2 minced garlic cloves and sauté for about 1 minute until fragrant. Stir in 1 cup of lobster meat, 1 cup of crab meat, and 1 cup of shrimp. Cook for 2-3 minutes until the seafood is heated through but not overcooked. Remove from heat and set aside to cool while you prepare the filling.

In a mixing bowl, combine the sautéed seafood with 8 ounces of cream cheese and 1 cup of shredded mozzarella. Season with salt and pepper to taste. Mix thoroughly until all ingredients are well blended.

In a large pot, bring salted water to a boil. Carefully add 12-15 jumbo pasta shells and cook according to package instructions until al dente, about 8-10 minutes. Once cooked, drain the shells and set them aside to cool slightly.

In the same skillet used for the seafood, melt another 2 tablespoons of butter over medium heat. Whisk in 2 tablespoons of flour, cooking for about 1-2 minutes to create a roux. Gradually add 1 cup of heavy cream while stirring, until the sauce is smooth and begins to thicken. Stir in ½ cup of grated Parmesan cheese until melted and creamy.

Preheat your oven to 375°F (190°C). Spread a thin layer of the creamy sauce in the bottom of a 9x13-inch baking dish. Stuff each of the cooled pasta shells generously with the seafood filling, then place the stuffed shells in the dish. Pour the remaining sauce evenly over the top.

Cover the baking dish with aluminum foil and bake in the preheated oven for 20 minutes. After this time, remove the foil and bake for an additional 10 minutes or until the sauce is bubbling and lightly golden.

Allow the seafood stuffed shells to cool for a few minutes before serving. Garnish with extra Parmesan cheese or fresh herbs.