Prepare the Seafood: Melt 2 tablespoons of butter in a large skillet over medium heat. Add 2 minced garlic cloves and sauté for about 1 minute until fragrant. Mix in 1 cup of chopped lobster meat and 1 cup of crab meat, cooking for an additional 2-3 minutes until warmed through. Remove the skillet from heat and set aside to cool.

Make the Filling: In a large mixing bowl, combine the sautéed seafood mixture with 8 ounces of softened cream cheese, 1 cup of shredded mozzarella, and a pinch of salt and pepper. Stir until the filling is creamy.

Cook the Jumbo Shells: Boil a pot of salted water. Add 20 jumbo pasta shells and cook according to package instructions for 9-11 minutes until al dente. Drain and rinse under cold water to prevent sticking. Set aside to cool.

Prepare the Sauce: Melt 2 tablespoons of butter in the skillet. Whisk in 2 tablespoons of flour until smooth; cook for 1 minute. Gradually pour in 1 cup of heavy cream, whisking to prevent lumps. Stir in ½ cup grated Parmesan and 1 cup shredded mozzarella. Cook until thick and creamy, about 3-5 minutes.

Assemble the Dish: Preheat oven to 375°F (190°C). Spread a thin layer of cheese sauce on the bottom of a 9x13-inch baking dish. Stuff each shell with the creamy filling, placing them seam-side up. Pour the remaining cheese sauce over the top.

Bake: Cover the dish with foil and bake for 20 minutes. Remove the foil and bake for another 10 minutes until bubbly and golden.

Serve: Let cool for 5 minutes. Garnish with extra Parmesan or fresh herbs. Serve warm.