In a skillet over medium heat, melt ½ tablespoon of butter and sauté 2 minced garlic cloves until fragrant, about 1-2 minutes. Add 1 cup of lobster meat and 1 cup of crab meat, cooking for an additional 2-3 minutes until heated through. Remove from heat and set aside to cool.

In a large mixing bowl, combine the cooked seafood with 8 ounces of cream cheese and 1 cup of shredded mozzarella. Stir until the ingredients meld together, then season with salt and pepper to taste.

Bring a large pot of salted water to a boil and gently add jumbo pasta shells. Cook according to package directions until al dente, usually around 9-12 minutes. Drain and cool slightly under cold running water.

In the same skillet, melt the remaining ½ tablespoon of butter over medium heat. Whisk in 2 tablespoons of flour and cook for about 1 minute. Gradually add in 1 cup of heavy cream while stirring, then mix in ½ cup of grated Parmesan cheese and 1 cup of shredded mozzarella.

Preheat oven to 375°F (190°C). Spread a thin layer of the cheese sauce in a baking dish. Stuff each shell with the seafood mixture and arrange them in a single layer. Pour the remaining sauce over the shells.

Cover the baking dish with aluminum foil and bake for 20 minutes. Remove the foil and bake for an additional 10 minutes until bubbly and golden brown.

Allow to cool for 5 minutes before serving. Garnish with extra Parmesan cheese or fresh herbs.