Cheesy Scalloped Potatoes
- PREP 30min
- COOK 45min
- TOTAL 1hrs 15min
These cheesy scalloped potatoes are divine thanks to a rich cream sauce made even more tasty with sweet onion, thyme, and Gruyère cheese. If you have trouble finding Gruyère, feel free to substitute a medium cheddar.
You Will Need
2 pounds Yukon Gold Potatoes (907g)
3 tablespoons butter, plus more for the dish (42g)
½ cup finely minced sweet onion, about ½ medium onion
2 tablespoons all-purpose flour
1 ½ cups whole milk (355ml)
½ cup heavy cream (118ml)
¾ teaspoon fine sea salt
¼ teaspoon fresh ground black pepper
¼ teaspoon garlic powder
1 teaspoon fresh thyme leaves, chopped
1 ½ cups shredded Gruyère, 6 ounces (170g)
Directions
1Prep: Preheat the oven to 375°F. Grease an 8×8-inch baking dish with butter.
2Cook the onions: In a medium saucepan, melt 2 tablespoons of the butter over medium heat. Add the onions and a small pinch of salt, then cook until the onions are soft and smell sweet, about 5 minutes.
3Make the sauce: Whisk in the flour to form a roux and cook for 1 minute. Slowly whisk in the milk and cream. Cook, whisking often, until the mixture is smooth and thickened. Season with the salt, pepper, garlic powder, and thyme.
4Add the remaining 1 tablespoon of butter and 1 cup of the Gruyère cheese. Whisk until the cheese melts and the sauce is smooth. Taste, and then adjust with a bit more salt as needed.
5Prep the potatoes: You can peel the potatoes or leave the peels on. Slice them into ⅛-inch thick rounds.
6Assemble: Spoon a thin layer of sauce into the bottom of the prepared baking dish. Add a layer of potato slices, slightly overlapping them like shingles. Sprinkle a little cheese over the potatoes, then spoon more sauce on top.
7Repeat the layering (potatoes, cheese, sauce) until all potatoes are used, ending with a final layer of sauce and the remaining cheese on top.
8Bake: Bake uncovered until the top is golden brown and a skewer slides easily through the potatoes, 40 to 55 minutes. Let the potatoes rest for 20 minutes before serving so they set and become easier to scoop.
Adam and Joanne's Tips
- Storing: Allow to cool, then refrigerate for up to 3 days. Reheat in the microwave or in a 375°F oven, covered with foil. We do not recommend freezing this dish due to its high dairy content.
- Make ahead: Assemble the casserole a day in advance, cover with plastic wrap, and refrigerate overnight. Uncover and bake the next day, adding a few extra minutes to account for the cold potatoes.
- Prep potatoes ahead of time: Peel the potatoes and slice them into ⅛-inch thick rounds. If you are not assembling the dish right away, place the slices in a bowl of water and keep them submerged to prevent browning.
- To make this in a 9×13 dish: Double all of the ingredients and follow the same method. Bake at 375°F until the top is golden and a skewer slides easily through the potatoes, about 55 to 65 minutes. Let the dish rest for 20 minutes before serving. This will serve 12 to 14 people.
- Best potatoes: Use red or yellow potatoes, rather than baking (Russet) potatoes. They hold their shape better. If you must use russets, peel them.
- The nutrition facts provided are estimates.