Description
These Cheesy Scalloped Potatoes are the ultimate comfort side-dish, featuring thinly sliced Yukon Gold or Russet potatoes layered with caramelized onions and bathed in a rich cheddar cheese sauce. The final bake yields tender, golden-topped potatoes with gooey, creamy interiors, perfect for family gatherings, holidays, or weeknight dinners.
Ingredients
Units
Scale
For the Onions:
- 2 tablespoons butter
- 1 tablespoon olive oil
- 1 large yellow onion, cut into 1/4-inch strings
- 1/2 teaspoon dried thyme
For the Cheese Sauce:
- 4 tablespoons butter
- 2 cloves garlic, minced
- 4 tablespoons flour
- 3 cups milk
- 2 tablespoons cream cheese, softened
- 3 1/2 cups shredded orange cheddar cheese, divided
- 1/2 teaspoon mustard powder
- 1/2 teaspoon salt
- 1/4 teaspoon pepper
- 1 pinch cayenne pepper
For the Potatoes:
- 2.5 lbs Yukon Gold or Russet potatoes (about 6 medium), peeled and sliced into 1/8-inch thick rounds
Optional Garnish:
- Fresh parsley, chopped
Instructions
- Preheat Oven – Preheat your oven to 350°F (175°C) to ensure it’s ready for baking once the assembly is finished.
- Caramelize the Onions – In a large skillet, melt 2 tablespoons butter with olive oil over medium-low heat. Add the sliced onions and thyme and cook slowly for about 30 minutes, stirring every few minutes, until the onions are deeply browned and caramelized. Remove from the skillet and set aside.
- Prepare the Cheese Sauce Base – In the same skillet or a clean pot, increase the heat to medium and add 4 tablespoons butter along with minced garlic. Sauté for 1 minute, then sprinkle in flour and whisk constantly for another minute to eliminate the raw taste of flour.
- Add Milk and Simmer – Gradually pour in the milk, whisking continually to avoid lumps. Once all milk is added and the sauce is smooth, bring to a gentle boil, then remove from heat.
- Season and Add Cheese – Stir in the mustard powder, salt, pepper, and cayenne. Let the sauce cool slightly, then reserve 1 heaping cup cheddar cheese for topping and gradually whisk the remaining cheese into the sauce. Add cream cheese and whisk until smooth. Stir in the caramelized onions.
- Prepare the Potatoes – Meanwhile, peel and rinse the potatoes. Pat dry and slice them into even 1/8-inch thick rounds for even cooking.
- Assemble the Casserole – Lightly grease a 9 x 13-inch baking dish. Arrange half of the sliced potatoes evenly at the bottom. Pour over half of the cheese sauce. Layer the remaining potatoes and top with the rest of the sauce. Finish by sprinkling with the reserved cheddar cheese.
- Bake – Cover the dish with foil and bake for 45 minutes. Remove the cover and continue to bake for another 40 minutes, until the potatoes are very tender and bubbling.
- Optional Broil – For a crispy, browned top, broil the casserole at 400°F for a few minutes, watching closely so it doesn’t burn.
- Rest and Serve – Allow the casserole to sit for 5-10 minutes after removing it from the oven to set up. Garnish with chopped fresh parsley before serving if desired.
Notes
- Caramelizing the onions is optional; you can soften them for quicker prep or skip if desired.
- For best melting and texture, shred your own cheese from a block instead of using pre-shredded cheese.
- Try mixing gruyere, mozzarella, or parmesan with cheddar for a more complex flavor.
- The sauce may seem plentiful but potatoes absorb a lot—this ensures a creamy, cheesy final result, even for leftovers.
- To make ahead: Assemble and bake covered for 45 minutes, cool completely, then refrigerate. When ready to serve, top with final cup of cheese and bake at 350°F for 55 minutes, broiling at the end for a crispy top.
- This dish can be made in a slow cooker by layering as directed and cooking on low for 7-8 hours.
Nutrition
- Serving Size: 1/8 of recipe
- Calories: 425
- Sugar: 5g
- Sodium: 600mg
- Fat: 25g
- Saturated Fat: 14g
- Unsaturated Fat: 9g
- Trans Fat: 0g
- Carbohydrates: 38g
- Fiber: 3g
- Protein: 14g
- Cholesterol: 65mg
