Gratinate

To gratinate is to brown the top of a dish so it forms a crisp, golden crust. The top is usually covered with grated cheese, breadcrumbs, butter or a sauce such as béchamel, then put under a hot broiler (grill in the UK) or into a very hot oven. A dish finished this way is served au gratin or gratinée. The word comes from the French gratin, the crust that forms in the dish.

How to do it

1. Cook the dish fully first. Gratinating only browns the top.
2. Put it in a shallow, ovenproof dish that can take direct heat, such as enameled cast iron or ceramic made for broiling.
3. Scatter an even layer of grated cheese, breadcrumbs or panko over the top. Dot with butter or drizzle with oil.
4. Place the dish 10 to 15 cm (4 to 6 inches) under a hot broiler, or in an oven at 220 to 230°C (425 to 450°F).
5. Watch it. Under a broiler it usually takes 2 to 5 minutes.
6. Rest for 5 minutes before serving so the crust sets.

How to tell it is done

The top is golden brown with darker spots, the cheese bubbles, and the sauce bubbles around the edges. Breadcrumbs should look crisp and toasted.

How to use it

• Potato gratin dauphinois and other gratins.
• French onion soup, finished with toasted bread and cheese.
• Macaroni and cheese, cauliflower cheese, baked pasta.
• Vegetables, fish or mussels in a cream or cheese sauce.

Common mistakes

• Using a dish that is too deep. The top browns before the middle is hot. Heat the dish through in the oven first, then gratinate.
• Fine, wet cheese only. Mix a hard, dry cheese such as Parmesan or Gruyère with crumbs for a crisp crust.
• Glass dishes under a broiler. They can crack.
• Adding the topping too early. It burns or dries out during long baking.