Sheet Pan Scalloped Potatoes

3.10 from 10 votes

Course: Dinner

Servings:

Calories: 295kcal

Preheat your oven to 375°F and grease a large baking sheet with a bit of the butter. Set aside.
Using a sharp knife or a mandolin, thinly slice the potatoes to about 1/8-inch thick and set them aside.
In a large saucepan over medium heat, melt the butter. Once the butter is melted, add the minced garlic and cook until it becomes fragrant, which usually takes about 1 minute.
Whisk in the flour to create a roux, cooking for about 2 minutes until it's golden brown.
Slowly whisk in the chicken broth, and continue to cook until the mixture thickens slightly.
Next, gradually whisk in the milk. Season the mixture with seasoning salt and pepper. Continue to cook and stir until the sauce has thickened.
Arrange a layer of the thinly sliced potatoes on the prepared baking sheet. Pour a bit of the sauce over the potatoes, ensuring they are well-coated. Sprinkle a portion of the grated cheddar over the top.
Repeat this process, creating multiple layers of potatoes, sauce, and cheese until you've used up all the ingredients, making sure you end with a layer of cheese on top.
Cover the baking sheet with aluminum foil and place in the preheated oven. Bake for 40 minutes, then remove the foil and continue baking for an additional 15-20 minutes, or until the potatoes are tender and the top is golden brown.
Once cooked, remove the sheet pan scalloped potatoes from the oven and allow them to cool slightly before serving.

Helpful Cooking Notes

Before we part ways, here are a few tips to ensure your sheet pan scalloped potatoes turn out just perfect:

Using a mandolin for slicing your potatoes will give you consistent thickness, leading to even cooking. Plus, it makes you feel like a real pro in the kitchen.
The key to getting that creamy sauce is the roux. Remember to cook it until golden brown, so you get that nutty, toasted flavor.

Refrigerate them in a sealed container, and they should last about 3-4 days.
To reheat, I recommend warming them in the microwave, covered by a damp paper towel in 45 second increments until warmed through. Or, if you have an air fryer, place the scalloped potatoes in an oven-safe dish and heat them at 350 degrees F for 7-10 minutes until heated through. (Using an air fryer will also bring back that crispy, cheesy topping!