In a large skillet, heat 2 tablespoons of butter over medium heat. Sauté 2 minced garlic cloves for 1 minute until fragrant, then add 1 cup of chopped lobster and 1 cup of crab meat. Cook for 2-3 minutes until heated through.

In a mixing bowl, combine the sautéed seafood with 8 ounces of cream cheese and 1 cup of shredded mozzarella. Season generously with salt and pepper.

Bring a large pot of salted water to a boil. Cook the jumbo pasta shells for 8-10 minutes until al dente. Drain and cool slightly.

In the same skillet, melt 3 tablespoons of butter over medium heat. Whisk in 3 tablespoons of flour for about 1 minute, then gradually add 2 cups of heavy cream while whisking until thickened.

Preheat your oven to 375°F (190°C). Spread a thin layer of sauce in the bottom of a baking dish. Stuff the pasta shells with the seafood filling and arrange them in the dish.

Pour the remaining cheese sauce over the stuffed shells and cover with aluminum foil. Bake for 20 minutes, remove foil, and bake for an additional 10 minutes until bubbly.

Allow to cool for a few minutes before serving. Optionally, garnish with extra Parmesan cheese or fresh herbs.