What is the meaning of Au Gratin in cooking?

Au gratin is a French culinary technique that involves baking food with a topping of cheese, breadcrumbs, and butter until it is golden brown and bubbly. The word gratin comes from the French word gratter, which means "to scrape". This refers to the way that the cheese and breadcrumb topping is scraped onto the food.

Au gratin dishes can be made with a variety of different ingredients. Some common choices include potatoes, cauliflower, broccoli, and pasta. The cheese most commonly used in au gratin dishes is Gruyère, but Parmesan and cheddar can also be used.

To make an au gratin dish, the food is first cooked until it is tender. It is then placed in a baking dish and covered with a mixture of cheese, breadcrumbs, and butter. The dish is then baked until the topping is golden brown and bubbly.

Au gratin dishes can be served as a main course or as a side dish. They are a delicious and versatile way to prepare a variety of different foods.