That signature brown crust can be achieved in a number of ways. The top of the dish can be generously sprinkled with breadcrumbs or cheese or smothered in a cream sauce; the cream sauce can also contain eggs, which gives it a richer and more custard-like texture. Gratins are then baked in a hot oven. If the gratin is hot and bubbly, but the top hasn’t yet browned, the gratin can be finished under the broiler to get a little color on the top.
A “gratin dish” is the actual vessel the gratin is cooked in, which is usually a wide, shallow, porcelain dish. The dish is brought right to the table, and the gratin is served straight from the baking dish. A gratin dish can be large for family-style meals or small for individually portioned gratins. What a way to bring excitement to a dinner party and a great excuse to go shopping for new dishes at a kitchenware store.
Vegetable gratins make an excellent side dish for a roast chicken or roast beef tenderloin. We often think of a potato gratin (also called potatoes au gratin, scalloped potatoes, or gratin dauphinois), but many other vegetables are suited for gratins, such as leeks, fennel, onions, tomatoes, zucchini, eggplant, cauliflower, greens (e.g., spinach or swiss chard), or butternut squash. Slice the vegetables thinly and arrange them in nice layers in your gratin dish. After each layer, sprinkle with cheese, dot with butter, or even toss in a few breadcrumbs for texture. You can also sneak in herbs, garlic or pieces of cooked bacon. When you are done layering, pour a cream sauce over the top and finish with more cheese or breadcrumbs. Stick with a solo vegetable, or mix a few together for variety.
However, gratins aren’t just for vegetables. Picture shredded chicken and broccoli coated in a parmesan cream sauce and baked until bubbly and browned or a Greek moussaka with eggplant and ground lamb or beef and a top layer of creamy custard that is browned in the oven. And we can’t forget baked mac ‘n cheese with chunks of ham or spicy sausage topped with buttered breadcrumbs that crisp up as it bakes.
Gratins are perfect for a make-ahead meal. Assemble the entire gratin in advance and store in the refrigerator. Just pop it in the oven to bake when mealtime approaches.