If cheese is added to a gratin, what does it become?

When cheese is added to a gratin, it becomes known as an "Au gratin" dish. The term "Au gratin" specifically refers to a style of cooking that involves a dish being topped with a mixture of cheese and breadcrumbs, which is then browned in the oven. The addition of cheese contributes a rich flavor and facilitates that appealing golden crust when baked, which is characteristic of these dishes.

In contrast, "Savoyard" typically refers to a type of dish or preparation that might include potatoes or other ingredients, but it does not inherently denote the addition of cheese in the same way "Au gratin" does. Similarly, "Ramekin" describes a small dish used for baking and serving, but does not define the style of preparation concerning cheese. "Gratin dauphinois" is a specific type of gratin focused on potatoes and cream rather than being a general category that incorporates cheese. Thus, the correct designation for a gratin to which cheese has been added is "Au gratin," capturing its essence and culinary technique.