Both made from thinly sliced potatoes that are baked in the oven, scalloped and gratin potatoes look similar. However, gratin potatoes always include cheese, which sets them apart.

The French term “au gratin” is often interpreted as a dish with grated cheese. Gratin is a cooking technique of making a dish with a browned crust using cheese and breadcrumbs.

The flat, oval-shaped baking dishes used to create gratin dishes are also called gratins, which are either made from heavy, oven-safe ceramic or tri-ply stainless steel.

Besides potatoes, you can make gratin from many vegetables, including broccoli. Slice and layer them with cream sauce, cheese, and breadcrumbs before baking until brown.

Scalloped potatoes, on the other hand, aren’t usually made with cheese and breadcrumbs and consists mainly of just potatoes and a heavy cream sauce, usually made with a roux.

Scalloped potatoes are usually sliced a little thicker than with a gratin, so the casserole is deeper. They are thought to be named for their resemblance to thinly sliced meat.

It could be argued that these two dishes are nearly the same, but if you want to be culinarily correct, remember that unless your gratin has cheese, it’s just scalloped potatoes.