Recipe: Scalloped Potatoes with Onions and Cheddar Cheese — Recipes from The Kitchn |Cooking With Amanda

October officially kicks off comfort food season (in my house at least), and these cheesy scalloped potatoes are a decadent way to welcome in the fall. Even if you are cooking for two, there is nothing better than having a pan of these to graze from, whether it's breakfast or dinner, throughout the week.

Scalloped potatoes is the American name for potatoes gratiné. I've always felt the French version seemed a little "fancy" if you know what I mean — delicious, don't get me wrong, but best reserved for special occasions. Scalloped potatoes, on the other hand, seem a bit more "everyday." (Perhaps this is because, like many people my age, I probably first encountered them straight from a box.)

Of course there are millions of variations on the recipe, but they all usually consist of layers of thinly sliced potatoes bathed in a thick sauce of milk or cream. Plenty of variables come into play (milk or cream, Parmesan or Gruyere, fresh herbs or not) but really it all comes down to the preference of the cook. The fun is in the finding out!

Both baking potatoes, such as Russets, and boiling potatoes, like Yukon Gold, work in these types of recipes. Baking potatoes are low-moisture, meaning they won't hold their shape as well as other types but all their starches will help create a thick, silky sauce. Boiling potatoes will hold up a bit better during baking and remain more firm. I just say use what you have on hand or what you know you like.

When it comes to cooking the potatoes, some recipes call for baking them low-and-slow, but I prefer par-cooking the potatoes on the stovetop before they go in the oven, which ensures the potatoes are seasoned evenly throughout. You can use water, stock, milk, or cream, or any mix of the two to parboil the potatoes. (Sometimes flour is also added to help thicken the sauce. I don't use it in this recipe, but I might had I used boiling potatoes or wanted to eliminate the heavy cream.)

Scalloped potatoes are definitely a recipe worth keeping in your arsenal, especially for those for nights when you deserve an extra special treat. These are scrumptious served warm from the oven but I think they get even better as they cool. In fact, I actually prefer them cooked and reheated the next day!

Scalloped Potatoes with Onions and Cheddar Cheese

Serves 6 to 8

2 tablespoons unsalted butter
1 medium onion, thinly sliced
4 cups whole milk (or 2 cups milk and 2 cups water)
2 to 3 garlic cloves, smashed
1 heaping teaspoon Dijon mustard (or dry mustard powder)
2 1/2 pounds (about 6 medium) baking potatoes, peeled
1 1/2 cups grated cheddar cheese, divided
3/4 cup heavy cream
Kosher salt and freshly ground black pepper

Preheat oven to 375°F. Lightly grease a medium sized (1-1/2 to 2 quart) gratin or baking dish.

In a large Dutch oven, melt the butter over medium heat. Add onions and sauté until softened, about 5 minutes. Add the milk, garlic, and Dijon and bring to a gentle boil over medium heat. Add a generous amount of salt and pepper.

Meanwhile, slice the potatoes to 1/8-inch thickness, using a food processor or mandoline for even thickness. (Do not rinse.) Add the potatoes to the milk and allow to simmer until the potatoes are almost tender — they should still have some resistance when poked with a pairing knife — about 10 minutes.

Using a slotted spoon, transfer half of the potatoes and onions to the baking dish. Season generously with salt and pepper and top with 3/4 cup cheddar cheese. Cover with the remaining potato mixture, season again with salt and pepper and top with remaining cheese.

Bake until crisp and golden on top, 50 minutes to 1 hour. Allow to cool for at least 10 minutes before serving. (Leftovers make a perfect breakfast side.)