Name: Instant Pot Scalloped Potatoes
Prep time: 15 min
Cook time: 25 min
Total time: 60 min
Ingredients: 1 ½ cups vegetable broth (can sub chicken broth ); 1 teaspoon dry mustard powder; ½ teaspoon garlic powder; ½ teaspoon onion powder; ½ teaspoon kosher salt; ¼ teaspoon dried thyme leaves (or 1 teaspoon fresh thyme leaves, chopped); 3 lbs russet potatoes, peeled and ¼-inch slice (see note 1 for prep tip); 1 cup milk; ¼ cup butter, melted (salted or unsalted); ¼ cup all-purpose flour; 1 ½ cups freshly grated sharp cheddar (divided)

Instant Pot Scalloped Potatoes are classic comfort food. This version has a generous amount of creamy sauce and is topped with sharp cheddar cheese. We love to serve this side dish with ham or a roast for Christmas and Easter meals!

Instant Pot Scalloped Potatoes in a white casserole dish, next to a gold and white serving spoon, viewed from overhead.

Whether you call this dish scalloped potatoes or potatoes au gratin, one thing is certain – they are amazingly delicious. We love to use a pressure cooker for scalloped potatoes for two reasons: first, it comes together more quickly than traditional oven-baked scalloped potatoes, and second, you’re guaranteed to have evenly cooked potatoes every time.

Ingredients

Below is an overview of the ingredients and steps to make Instant Pot Scalloped Potatoes. See the recipe card below for all the details!

Russet potatoes – perfect for scalloped potatoes because the starchiness of this variety will help thicken the sauce and the longer, more uniform shape makes them easier to slice. You can substitute with Yukon Gold potatoes.
Vegetable broth – you can also use chicken broth if the dish doesn’t need to be vegetarian. The broth provides the liquid for the Instant Pot to come to pressure, while giving flavour to the sauce.
Seasonings – we use a mix of dry mustard powder, onion powder, garlic powder, salt and thyme.
Milk – to give volume to the sauce
Melted butter and flour – whisked in after pressure cooking to the thicken the sauce. This is my less messy version of a beurre manié, like I use in my Instant Pot Chicken Pot Pie.
Sharp cheddar – for amazing, tangy, savoury flavour. You can also use regular cheddar if that’s what you have on hand.

Ingredients needed to make Instant Pot Scalloped Potatoes, viewed from overhead.

How to make it

First, pour the broth into the insert, then add the dry mustard powder, garlic powder, onion powder, salt and thyme.

Next, evenly layer the peeled and sliced potatoes into the steamer basket, then place the basket in the pot over the broth.

Step one: broth and seasoning in the Instant Pot, then step two: sliced potato rounds in a steamer basket in the Instant Pot.

Pressure cook on High for 1 minute, then let the pressure release naturally for 2-3 minutes before quick releasing the remaining pressure. Meanwhile, preheat the oven to 375 °F and grease a 2.5-quart baking dish.

Once the pressure is released, carefully remove the steamer basket with the potatoes and set aside. Leave the liquid in the pot and turn on the Sauté function to low. Whisk in the milk and bring to a simmer.

Whisk together the melted butter and flour until smooth, then whisk it into the broth mixture. Continue to stir until thickened, about a minute, then stir in half a cup of cheese and transfer the liner from the Instant Pot to a heat-safe surface.

Melted butter and flour mixed together in a white bowl, over a photo of the finished sauce in the Instant Pot insert.

Layer half the potatoes into the casserole dish (carefully, the potatoes are soft!), then pour on half the sauce and sprinkle with a half cup of grated cheddar. Repeat with the remaining potatoes, sauce and cheddar.

Bake for 10-15 minutes until the sauce is bubbling around the edges. Optionally, you can broil for an additional 5 minutes until the top is turning golden brown.

Scalloped Potatoes in a white casserole dish, top with sharp cheddar, before going in the oven.

Tips for Success

Soak peeled and sliced potatoes in cold water during prep. This will help prevent the starch in the potatoes from oxidizing and turning that black/brown/grey colour.
Use a steamer basket. I tested this recipe without the steamer basket, but the potatoes at the bottom get very overcooked and are hard to remove from the liquid. The basket makes it a breeze to transfer the potatoes out of the pot.
Don’t skip the 2-3 minute natural release. We tested this with just 1 minute of cooking time then quick release, but a few of the potato slices were a bit too hard. The short natural release solved this problem!

Be gentle with the cooked potato slices. It can be tricky to transfer the cooked potatoes to the casserole dish and it’s totally fine if some of the pieces break because you’re covering it with sauce anyway. It’s a small price to pay for the guarantee of perfectly cooked potatoes!
Remove the sauce from heat as soon as it is cooked. Use the low sauté setting and remove it from heat right away so that it doesn’t burn to the bottom of the liner. You may see the “HOT” message on the screen once you thicken the sauce – not to worry, as long as you continue to stir while it’s still over the heat and remove it from heat promptly after stirring in the cheese.

Variations

Add diced ham. This recipe is a great way to use leftover ham. You can use 1-2 cups of diced cooked ham and layer it into the casserole.

Omit the cheese. If you prefer to use a simple cream sauce, just leave out the cheddar! You’ll want to taste the sauce and adjust the the salt before layering it with the potatoes, because you’re losing the saltiness of the cheese.

Top with breadcrumbs if you’d like an extra crispy topping!

Instant Pot Scalloped Potatoes being scooped out of a white casserole dish.

How to thinly slice potatoes

The fastest way to uniformly cut quarter-inch slices of potato is to use a mandoline. Be sure to use the guard that comes with the mandoline and/or use a protective glove while slicing. If you don’t have a mandoline, simply use a sharp chef’s knife; it will just take a bit longer!

How to make ahead

You can assemble this potato casserole up to 3 days ahead of time. Follow the recipe as stated until it’s assembled, but instead of baking, cool to room temperature, then tightly cover and place in the refrigerator. The day of your meal, bake at 375 °F covered with foil for about 25 minutes or until the sauce is bubbling and the internal temperature reaches 165 °F, then broil for 5 minutes uncovered to brown the top.

How to reheat

Cover the casserole dish with foil and bake at 350 °F for about 30 minutes or until completely heated through to an internal temperature of 165 °F.

A serving of scalloped potatoes on a stack of white plates, in front of an Instant Pot and the casserole dish.

More Instant Pot side dish recipes

⭐️⭐️⭐️⭐️⭐️ If you enjoyed this recipe, please leave a review below! You can also subscribe to my newsletter and follow on Facebook, Instagram and TikTok to see the latest recipes and meal inspiration!