Melt 2 tablespoons of butter in a skillet and sauté 2 cloves of minced garlic until fragrant, about 1 minute. Add 1 cup of lobster meat and 1 cup of crab meat, stir gently for 2-3 minutes until heated through, then set aside to cool slightly.

In a mixing bowl, combine the cooled seafood with 8 ounces of cream cheese and 1 cup of shredded mozzarella cheese. Season with salt and pepper, mixing until well incorporated.

Bring a large pot of salted water to a boil and cook 12 jumbo pasta shells according to package instructions until al dente, about 8-10 minutes. Drain the shells and cool on a kitchen towel.

In the same skillet, melt 4 tablespoons of butter and whisk in ¼ cup of flour, cooking for about 2 minutes. Gradually add 1 cup of heavy cream and ½ cup of grated Parmesan cheese, stirring continuously until thick and creamy.

Spread a thin layer of the creamy sauce at the bottom of a 9x13-inch baking dish. Stuff each pasta shell with the seafood filling and place them in the dish, open side up. Pour the remaining sauce over the shells.

Preheat your oven to 375°F (190°C). Cover the baking dish with foil and bake for 20 minutes. Remove the foil and bake for an additional 10 minutes until golden and bubbly.

Let the shells cool for 5 minutes, garnish with fresh herbs, and serve warm.