Slow cooker cheesy scalloped potatoes are a generous, comforting side with tender potato slices tucked into a creamy cheddar sauce. A simple homemade sauce coats the layers without relying on canned soup, and a final handful of cheese melts over the top. The slow cooker frees the oven for the rest of dinner.
The golden finish in the photo comes from a brief optional trip under the broiler after the potatoes are fully cooked. You can skip that finish and serve them straight from the cooker; the sauce and tender layers are the same. Even slicing and checking the center for tenderness matter more than following the clock to the minute.
Recipe at a Glance
- Servings: 8 side portions
- Preparation: 25 minutes
- Cooking: 3 hours 15 minutes to 4 hours 20 minutes on HIGH, or 6 hours 15 minutes to 7 hours 20 minutes on LOW
- Optional broiling: 2–4 minutes
- Resting: 10 minutes
- Equipment: 6-quart slow cooker, saucepan, sharp knife or guarded mandoline
Ingredients
- 3 pounds Yukon Gold potatoes
- 3 tablespoons unsalted butter, divided for the cooker and sauce
- 1 small yellow onion, thinly sliced
- 3 garlic cloves, minced
- 3 tablespoons all-purpose flour
- 2 cups whole milk
- 1 cup heavy cream
- 2 cups freshly shredded sharp cheddar (8 ounces), divided
- 1/2 cup finely grated Parmesan
- 1 teaspoon kosher salt, or 1/2 teaspoon fine table salt
- 1/2 teaspoon ground black pepper
- 1/2 teaspoon dried thyme
- 1 tablespoon chopped parsley, optional
Ingredient Notes
Yukon Gold potatoes make creamy, distinct layers. Russets also work, but their edges soften more and they may absorb sauce differently. Freshly shredded cheddar melts more smoothly than some bagged cheeses. Whole milk and heavy cream give the sauce body; using only low-fat milk makes a thinner result. The flour helps bind the dairy sauce as it cooks.
How to Make Slow Cooker Cheesy Scalloped Potatoes
1. Prepare the potatoes and cooker
Lightly butter a 6-quart slow cooker using a little of the measured butter. Scrub and peel the potatoes, then cut them into even 1/8-inch slices. Thinly slice the onion and mince the garlic. A mandoline makes the potato slices consistent; use its hand guard.
2. Make the creamy cheese sauce
Melt the remaining butter in a saucepan over medium heat. Cook the onion for 4 to 5 minutes until softened, then stir in the garlic for 30 seconds. Sprinkle in the flour and stir for 1 minute. Gradually whisk in the milk and cream. Bring to a gentle simmer and cook for 3 to 4 minutes, stirring, until lightly thickened. Remove from the heat. Stir in 1 cup of the cheddar, the salt, pepper, and thyme until smooth.
3. Layer the potatoes and sauce
Spread a thin layer of sauce in the cooker. Add half of the sliced potatoes, spreading them evenly rather than packing them tightly. Spoon over half of the remaining sauce. Add the rest of the potatoes and finish with the remaining sauce, easing some down around the edges.
4. Slow-cook until completely tender
Cover and cook on HIGH for 3 to 4 hours or LOW for 6 to 7 hours. Begin checking near the early end of the range. A thin knife should slide easily through the potatoes in the center and near the edges. Keep cooking if you feel firm or crunchy slices; cooker strength and potato thickness affect the timing. Avoid lifting the lid repeatedly.
5. Melt the cheese topping
Sprinkle the remaining 1 cup cheddar and the Parmesan evenly over the tender potatoes. Cover and cook for another 15 to 20 minutes, just until the cheese melts. If the sauce seems loose, leave the lid off for the final 10 minutes and let the potatoes stand before serving.
6. Add a golden finish, if desired
For the browned top shown in the featured photo, gently transfer the cooked potatoes and sauce to a broiler-safe metal baking dish. Broil 6 to 8 inches from the heat for 2 to 4 minutes, watching constantly, until lightly golden. Do not put a slow-cooker insert under the broiler unless its manufacturer explicitly permits it. You can also serve directly from the cooker with a melted, unbrowned topping.
7. Rest and serve
Let the potatoes stand for 10 minutes so the sauce settles. Scatter with parsley if using, then scoop into portions, spooning sauce over each. Serve warm.
Tips for Tender, Creamy Layers
- Keep every slice close to 1/8 inch thick. A few thick pieces can stay firm after the rest are tender.
- Whisk the milk into the roux gradually so the sauce stays smooth. Melt cheese off the heat rather than boiling it.
- Do not rinse the sliced potatoes after cutting; their surface starch helps the sauce cling.
- Check the center, not just the browned edges of the cooker. Leave extra time if making this for a timed meal.
- Let the finished potatoes rest before scooping. The sauce thickens slightly as it stands.
Serving Suggestions
Serve with roast chicken, pork chops, ham, or a beef roast. Green beans, broccoli, or a sharp green salad balance the richness. These are filling side portions, so a smaller scoop works well on a holiday plate with several other dishes.
Make Ahead, Storage, and Reheating
Make the sauce up to 1 day ahead and refrigerate it promptly. Warm it gently with a splash of milk before layering, and slice the potatoes close to cooking time to limit browning. A cold assembled cooker takes longer to heat, so this recipe does not use an overnight assembled shortcut.
Refrigerate leftovers in shallow covered containers within 2 hours and use within 3 to 4 days. Reheat covered in the oven or microwave with a little milk until the center reaches 165°F (74°C). Freezing is possible for up to 2 months for best quality, but the potatoes and dairy sauce may become softer or slightly grainy after thawing. Thaw in the refrigerator before reheating.
Frequently Asked Questions
Why are the potatoes still hard?
They may be sliced too thickly, packed too tightly, or cooking in a cooler-running appliance. Keep the lid on and continue cooking until a knife passes easily through the center. Cheese melting on top does not prove the potatoes underneath are done.
Can I double the recipe?
Use a second cooker rather than filling one far more deeply. A deeper stack changes the heating pattern and can leave the center firm. Keep within your appliance’s recommended fill level.
Will the top brown in the slow cooker?
Usually it will melt rather than form an oven-style crust. Use the optional broiler finish in a suitable metal dish for a golden top.
Can I add cooked ham?
Yes. Fold in 1 to 1 1/2 cups of diced fully cooked ham while layering and reduce the added salt to taste. Keep the potato slices and sauce quantities the same.