Scalloped potatoes are a wonderful side dish made from thinly sliced potatoes and onions layered with a velvety cream sauce. These potatoes are rich, herby, and perfect with roasted meat and poultry.
Scalloped potatoes are a side dish we always look forward to.
On account of their rich and creamy consistency, they’re not something we eat all the time but are reserved for special occasions like holidays and gatherings.
We especially love scalloped potatoes for Easter because the green onions and thyme lend a Springtime vibe to the dish and they happen to pair really well with Easter roasts, like pork loin, glazed sprial ham, and leg of lamb.
How to make it
Each number corresponds to the numbered written steps below.
- Preheat the oven to 350f and set the rack to the middle level. Using a mandoline, slice 3 pounds of russet potatoes sliced to 1/8-inch thick, and 1 large onion to 1/16-inch thick. Chop 5 large green onions, mince 3 cloves of garlic, and remove 2 teaspoons worth of thyme leaves from their stems. Note: if you use a mandoline, be sure to use the guard for safety. If you do not have a mandoline, use a sharp chef’s knife to slice the onions and potatoes.
- Heat a saucepan to medium-low heat and add 4 tablespoons of butter and the minced garlic. Cook the garlic for 1-2 minutes or until fragrant.
- Add a 1/4 cup of all-purpose flour and cook until the flour turns golden, about 1-2 minutes.
- Add 3 cups of whole milk to the pot slowly while whisking to combine.
- Add the chopped green onions and turn the heat to medium-high and bring the sauce to a simmer while continuing to whisk. It will thicken quickly.
- Once simmering, turn off the heat and season the sauce with salt and pepper to taste.
- Grease a 9×13″ baking dish with butter, then place 1/3 of the sliced potatoes into the dish.
- Season the layer with 1/3 of the thyme, salt, and pepper.
- Add a layer of onion using 1/3 of the sliced onions.
- Ladle 1/3 of the cream sauce on top.
- Repeat the process for two more layers, then cover tightly with foil and bake for 50 minutes.
- Remove the foil and bake for another 30 minutes or until the potatoes are tender. For added color, broil the top for about 2-3 minutes but watch carefully to avoid burning. Let the potatoes rest for at least 15 minutes before serving. Enjoy!
- Potatoes. We used russets for this recipe because they tend to be on the larger side and are easier to slice on the mandoline, but if you’d like to use Yukon Golds, or other varieties of white potato, you can.
- Slicing. Similar to my Italian potato casserole, I used a mandoline to slice the potatoes and onions because it makes the job easier and ensures uniform thickness for each. If you do not own a mandoline, use a sharp knife to slice the ingredients. If you do use a mandoline, be sure to use the guard to avoid injury.
- Making ahead. While this scalloped potato casserole can be made ahead of time, it is probably best when eaten fresh as the sauce may dry out a bit.
- Herbs. I love using thyme for this recipe as it pairs perfectly with the creamy sauce and green onions, but you could use other herbs as well, such as parsley, rosemary, or tarragon.
More great side dishes
Here are a few more of our favorite side dishes. These are all perfect for the holidays!
- Baked asparagus – with breadcrumbs and lemon.
- Mashed potatoes – with roasted garlic.
- Roasted carrots – with maple syrup and parsley.
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- 3 pounds russet potatoes sliced to 1/8-inch thick
- 1 large onion thinly sliced
- 5 large green onions chopped
- salt and pepper to taste
For the cream sauce
- 4 tablespoons butter
- 3 cloves garlic minced
- 1/4 cup flour
- 3 cups whole milk
- 1 1/2 teaspoons kosher salt
- 1/2 teaspoon black pepper
- 2 teaspoons fresh thyme leaves only
- Preheat oven to 350f and set the rack to the middle level.
- Heat a saucepan to medium-low heat with the butter and garlic and cook until fragrant (about 1-2 minutes).
- Add the flour and cook for 1-2 minutes or until all of the white flour turns golden.
- Add the milk into the pot slowly while whisking to combine. Add the green onions and turn the heat to medium-high and bring to a simmer while whisking. Once the sauce simmers and thickens, remove the saucepan from the heat and season with salt and pepper to taste.
- Grease a 9x13" baking dish with butter then place 1/3 of the potatoes into the dish. Layer 1/3 of the sliced onion. Season each layer with salt, pepper, and thyme. Pour 1/3 of the cream sauce on top and repeat for the next two layers.
- Cover tightly with foil and bake for 50 minutes. Remove the foil and continue to bake until the potatoes are tender (~30 minutes). For added color, broil the top for around 2-3 minutes but watch carefully.
- Allow the scalloped potatoes to rest for at least 15 minutes to set before serving. Enjoy!
- Scalloped potatoes traditionally are not made with cheese, but feel free to add cheddar, parmesan, or any cheese you like to the cream sauce.
- Using a mandoline is recommended for both the potatoes and onion (cut to about 1/8" of thickness and the onions to 1/16" thickness).
- Leftovers can be saved in the fridge for up to 3 days and can be reheated in either the microwave or oven.
Nutrition information is automatically calculated, so should only be used as an approximation.