How to Make Scalloped Potatoes
Make the best bubbly, creamy, cheesy casserole of tender scalloped potatoes.
Scalloped potatoes are one of those foods that always feel festive. A bubbling, creamy, cheesy casserole of tender potatoes, sometimes bolstered with meat like ham or bacon, under a crust of melted cheese or crispy breadcrumbs. It is a classic side dish for holiday meals, especially since it can be made ahead and reheated, and the richness means that a little goes a long way, so a pan feeds a crowd. But if you did not grow up with scalloped potatoes on your table, they can feel a little bit daunting as a cooking project.
Luckily, they are simpler than you might imagine, and once you know the basics, endlessly adaptable by changing cheeses, add-ins, and toppings. You can make a scalloped potato an all-in-one meal by layering in a hearty layer of meat or topping with a fried or poached egg. Make a spicy version with pepperjack cheese or a smoky version with smoked gouda or cheddar. Get fancy with truffle butter or caramelized onions. The world is your scalloped potato oyster!
How to Make the Best Scalloped Potatoes
To begin, start with the basics. A scalloped potato is really just potatoes baked in a mornay sauce, a bechamel, or thickened milk gravy enriched with cheese, essentially the same mix you might use for a baked macaroni and cheese. In fact, little known secret, if you swap in thin-sliced potatoes for the cooked pasta in your favorite mac and cheese recipe, you will have scalloped potatoes!
This version bakes in a standard 10-inch cast iron skillet or 9x9 square casserole dish or small oval gratin dish, to heartily serve 4-6 people. If you want to make it larger in a deep 9x13, you can double the recipe.
For starters, peel and slice thinly about 2 pounds of potatoes, and set aside in a bowl of cold water to prevent browning and heat your oven to 350.
Then turn your attention to the mornay sauce. Start by making a roux with equal parts butter and flour, melting the butter in a skillet then adding the flour and cooking for a minute to ensure that the flour is cooked. Use two tablespoons of butter and two of flour and cook to a pale cream color. Slowly whisk in a cup and a half of milk and cook until it is thickened to a gravy consistency. Season well with salt and freshly ground pepper to taste. Once your base gravy has the consistency you want, whisk in 4 ounces of shredded cheese…use something that melts well but also brings flavor. Think white Cheddar, gruyere, smoked gouda, emmenthal, or fontina. Or use a blend of cheeses that you love. Add a tablespoon of grated Parmesan to boost the cheesy flavor. A pinch of nutmeg and/or cayenne will bring good seasoning to your sauce.
Once the sauce is made, you are ready to assemble! Drain the potatoes and pat dry with a clean kitchen towel. Butter your cooking dish well. Layer in half of your potatoes evenly but do not pack too tightly, you want some spaces for the sauce to flow into. Sprinkle with salt and pepper. Add half of your cheese sauce, nudging it into the spaces. If you want to add some extras like cubed ham or crumbled bacon or cooked crumbles of sausage or ground beef, add it here! This is also a good time to add fresh herbs like chopped parsley, thyme, or chives, or sliced scallions or caramelized onion. Then add the rest of the potatoes in a second layer, and finish with the rest of the sauce.
If you bake as-is, you'll get a browned bubbly top layer. Add more grated cheese on top if you want a crispy cheese layer, or sprinkle on buttered breadcrumbs if you prefer. You can make the dish to this stage and store in the fridge for up to three days before cooking. Be sure to remove from the fridge 2 hours before baking to let come to room temp before continuing with the recipe.
Cover the dish with aluminum foil and bake for 40 minutes. Remove the foil and continue to bake for another 15-20 minutes, until the top is browned, the dish is bubbling, and a knife slides into the potatoes easily with no resistance. Let cool 10 minutes before serving.
See also, 6 Mistakes to Avoid When Making Scalloped Potatoes. And don't miss our collection of Scalloped Potato Recipes.