Best Scalloped Potatoes with Mushroom Soup

Here’s my go-to recipe for scalloped potatoes with mushroom soup, featuring thin layers of tender potatoes, creamy mushroom soup, and plenty of melted cheese that creates the perfect comfort food casserole.

This dish shows up at every holiday gathering in our house, and for good reason – it’s simple to make and always leaves empty dishes at the end of the meal. I often make an extra pan just to have leftovers for lunch the next day. Because let’s be honest, these potatoes might taste even better reheated!

What Kind of Potatoes Should I Use?

While this recipe calls for gold potatoes, you’ve actually got several good options for making scalloped potatoes. Gold potatoes (also called Yukon Gold) are a great choice because they have a naturally buttery flavor and hold their shape well when cooked. Russet potatoes work nicely too, though they tend to break down a bit more during cooking. For the best results, try to slice your potatoes about 1/8 inch thick – a mandoline slicer makes this job much easier and helps ensure even cooking. Just make sure to avoid using red potatoes, as their waxy texture isn’t ideal for this creamy dish.

Options for Substitutions

This creamy potato dish is pretty adaptable – here are some handy swaps you can try:

• Gold potatoes: While gold potatoes give the best buttery texture, you can use russet or red potatoes too. Just keep the slices thin and consistent for even cooking.
• Cream of mushroom soup: Out of mushroom soup? Cream of chicken or cream of celery soup work great. For a vegetarian option, try cream of potato soup instead.
• Colby Jack and Cheddar cheese: Feel free to mix up the cheese combo – Monterey Jack, Gruyere, or even Mozzarella can work. Just make sure to use at least one medium-sharp cheese for good flavor.
• Sour cream: Plain Greek yogurt makes a good substitute for sour cream. If you’re out of both, you can add an extra 1/2 cup of milk instead.
• Bacon crumbles: These can be skipped for a vegetarian version, or replaced with ham bits. For a similar smoky taste without meat, try adding 1/2 teaspoon of smoked paprika.
• Full-fat milk: You can use 2% milk, but the sauce won’t be as rich. For extra creaminess, half-and-half works great too.

Watch Out for These Mistakes While Cooking

The biggest challenge when making scalloped potatoes is achieving even cooking – slicing your potatoes too thick or unevenly can lead to some pieces being undercooked while others turn mushy, so aim for uniform 1/8-inch thick slices (using a mandoline slicer makes this task much easier). Getting the sauce consistency right is crucial – rushing the roux by not cooking the flour and butter long enough can result in a grainy texture, so make sure to cook this mixture for at least 2-3 minutes until it’s golden and smells nutty. Another common mistake is uncovering the dish too early during baking – keep it covered with foil for the first 45 minutes to ensure the potatoes cook through properly, then remove the foil for the final 15-20 minutes to achieve that golden-brown top. For extra creamy results, let the casserole rest for 15 minutes after baking – this allows the sauce to thicken and settle, making it easier to serve and even more flavorful.

What to Serve With Scalloped Potatoes?

These rich and creamy scalloped potatoes make an excellent side dish that pairs wonderfully with simple protein options like baked chicken, grilled steak, or roasted pork chops. To balance out the richness of the potatoes, try serving them alongside some steamed green vegetables like broccoli, asparagus, or green beans. For a complete Sunday dinner spread, you could add a fresh garden salad with a light vinaigrette dressing and some warm dinner rolls. Since these potatoes are pretty filling, keeping the rest of your meal simple and straightforward is the way to go!

Storage Instructions

Keep Fresh: These creamy scalloped potatoes will stay good in the fridge for up to 4 days when stored in an airtight container. The cheese sauce might thicken up a bit in the fridge, but don’t worry – it’ll become creamy again when reheated!

Freeze: While you can freeze these potatoes, the texture might change a bit since dairy-based dishes can sometimes separate when frozen. If you decide to freeze them, they’ll keep for up to 3 months in a freezer-safe container. Just know they might not be quite as creamy as when fresh.

Reheat: To warm up your leftovers, pop them in the oven at 350°F for about 20-25 minutes, covered with foil. You can also microwave individual portions for 2-3 minutes, stirring halfway through. If the sauce seems too thick, just add a splash of milk while reheating.

Make Ahead: You can assemble this dish up to 24 hours in advance and keep it covered in the fridge. Just add an extra 10-15 minutes to the baking time when cooking from cold. This is super handy for holiday meal prep!

Preparation Time	20-30 minutes
Cooking Time	50-60 minutes
Total Time	70-90 minutes
Level of Difficulty	Medium

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 2200-2500
• Protein: 55-65 g
• Fat: 130-150 g
• Carbohydrates: 220-240 g

Ingredients

For the potatoes:

• 1 cup shredded mild cheddar cheese
• 6 medium gold potatoes (sliced into 1/8-inch rounds)
• 1 cup shredded Colby Jack cheese (I use Cabot brand)

For the sauce:

• 1 tsp garlic powder
• 1 cup full-fat milk (for creamier sauce)
• 3 tbsp butter (unsalted, melted)
• 1 tsp celery seed (freshly ground preferred)
• 3 tbsp all-purpose flour
• 1/3 cup bacon crumbles (freshly cooked preferred)
• 1/2 cup sour cream (room temperature)
• 1/2 tsp black pepper
• 1 tsp salt
• 1 can cream of mushroom soup
• 1/3 cup sweet onions (finely diced)

Step 1: Prepare Ingredients and Preheat Oven

• 6 medium gold potatoes, sliced into 1/8-inch rounds
• 1/3 cup sweet onions, finely diced
• 1/3 cup bacon crumbles
• 1 cup shredded Colby Jack cheese
• 1 cup shredded mild cheddar cheese
• 1/2 cup sour cream, room temperature

Preheat your oven to 350°F and lightly butter a 9×9 inch baking dish.

While the oven heats, slice the potatoes into 1/8-inch rounds (uniform thickness is key for even cooking) and immediately place them in a bowl of cold water to prevent browning and remove excess starch—this helps the potatoes cook more evenly and prevents a gluey texture.

Finely dice the sweet onions and set aside with the bacon crumbles, cheeses (measured and ready), and sour cream at room temperature.

Step 2: Build the Creamy Mushroom Sauce

• 3 tbsp butter, unsalted and melted
• 1/3 cup sweet onions, finely diced
• 3 tbsp all-purpose flour
• 1 cup full-fat milk
• 1 can cream of mushroom soup
• 1 tsp celery seed
• 1 tsp garlic powder
• 1 tsp salt
• 1/2 tsp black pepper
• 1/2 cup sour cream, room temperature

Melt the butter in a large pot over medium heat, then add the diced onions and sauté until softened, about 3-4 minutes.

Sprinkle the flour over the butter and onions, whisking constantly for 1-2 minutes to create a light roux—this prevents lumps in your sauce.

Pour in the milk and cream of mushroom soup together, whisking continuously until the mixture thickens slightly, about 3-4 minutes.

I like to use full-fat milk here because it creates a richer, more luxurious sauce that really elevates the dish.

Stir in the celery seed, garlic powder, salt, and black pepper, then remove from heat and gently fold in the sour cream until fully incorporated.

Step 3: Drain Potatoes and Begin Layering

• sliced potatoes from Step 1, drained and dried
• 1 cup shredded cheese
• creamy mushroom sauce from Step 2

Drain the potatoes from their cold water bath and pat them thoroughly dry with paper towels—excess moisture will dilute your sauce and prevent proper browning.

Begin layering in the prepared baking dish: spread 1/3 of the dried potatoes as the first layer, then sprinkle with 1/2 cup of the mixed cheeses (combine Colby Jack and cheddar), followed by 1/3 of the creamy mushroom sauce from Step 2.

The potato starch will help thicken the sauce further as it bakes, creating a cohesive, creamy texture.

Step 4: Complete Layering and Add Bacon

• sliced potatoes from Step 1
• 1 cup shredded cheese
• creamy mushroom sauce from Step 2
• 1/3 cup bacon crumbles

Repeat the layering: another 1/3 of potatoes, 1/2 cup cheese, and 1/3 of the sauce.

Finish with the final third of potatoes on top, then sprinkle the remaining 1/2 cup of cheese over the surface.

I like to scatter the bacon crumbles between the final layer of potatoes and the top cheese layer—this way they get slightly crispy during baking while still staying embedded in the dish rather than getting too dark on top.

Step 5: Bake Until Golden and Tender

Place the baking dish in the preheated 350°F oven and bake for 50-60 minutes, until the top is golden brown and the potatoes are fork-tender when pierced.

The casserole will bubble slightly around the edges when fully cooked.

For the best texture, avoid opening the oven door during the first 40 minutes—this keeps the heat consistent and allows the potatoes to cook evenly.

Let it rest for 5 minutes out of the oven before serving; this allows the sauce to set slightly and makes serving cleaner.