Leek and Ham Gratin is a delicious and comforting dish that combines tender leeks, savory ham, and creamy cheese sauce. The leeks are sautéed until soft and then layered with ham in a baking dish. A rich cheese sauce made with butter, flour, milk, and grated cheese is poured over the leeks and ham. The dish is then baked until golden and bubbly. This gratin is perfect as a side dish or a main course served with crusty bread.