Seafood au gratin is a rich and creamy dish that combines a variety of seafood with a cheesy sauce. The seafood, such as shrimp, scallops, and crab, is cooked until tender and then combined with a creamy sauce made from butter, flour, milk, and cheese. The mixture is then baked until golden and bubbly, creating a delicious and indulgent seafood dish. Serve the seafood au gratin as a main course with a side of crusty bread or over pasta for a complete meal.