Both scalloped potatoes and potatoes au gratin consist of sliced potatoes baked in a creamy sauce and topped with crunchy crumbs, so you’d be forgiven for mixing up the two. Au gratin, by definition, means “covered with breadcrumbs or cheese and then baked until brown,” while scalloped potatoes are baked in a creamy sauce and covered with seasoned bread or cracker crumbs. The big difference between the two, then, is the cheese component.
Here’s where things get confusing: Although scalloped potatoes don’t call for cheese, and both scalloped and au gratin potatoes can be topped with breadcrumbs, many recipes add cheese to the former or eliminate the breadcrumbs entirely—hence perpetuating the idea that the two dishes are interchangeable.
When making either, choose a tuber that holds its shape and firmness when baked in a creamy liquid, such as a red or Yukon gold potato. Many recipes call for russet potatoes, but The Kitchn suggests that this classic ‘tater falls apart in a scalloped or au gratin dish.
Making Potatoes Au Gratin
A standard recipe for creamy potatoes au gratin calls for peeled potatoes combined with heavy cream, milk, flour, garlic, butter, cheddar cheese, salt, and pepper, plus a sprinkling of chopped fresh parsley for garnish. Create interesting variations with different cheeses. Here are some options:
- Stilton, if you like the strong favor of bleu cheese
- Gouda, for a smoky flavor
- Pepper jack, for a bit of spice
For a little something extra, sprinkle in chopped cooked bacon, or replace half the sliced potatoes with rutabagas or turnips.
Making Scalloped Potatoes
Because scalloped potatoes don’t call for any cheese, the recipe is a bit simpler.
Combine sliced potatoes with butter, heavy cream, whole milk, and a bit of grated nutmeg, plus salt and pepper to taste. Sprinkle buttered breadcrumbs on the top before baking. Try any of the following variations as well:
- Replace standard potatoes with sliced sweet potatoes.
- Add a tablespoon of horseradish to the sauce for a little kick.
- Sprinkle in diced ham and chopped bell peppers to make it a main dish for breakfast, lunch, or dinner.