Creamy, cheese-crowned Ham and Cheese Scalloped Potatoes turn leftover ham into a comforting, science-backed potato casserole masterpiece.
- Starch Gelatinization: Slicing the potatoes to exactly 1/8-inch allows their natural starches to thicken the milk-based sauce into a velvety glaze without turning gummy.
- Roux-Based Stability: A classic butter-and-flour roux prevents the dairy from curdling under the high heat of a long bake.
- Swiss Cheese Synergy: Swiss cheese brings a sharp, nutty contrast that cuts through the salty richness of the ham and the earthy potatoes.
I still remember standing at my grandmother's laminate counter on a damp November afternoon, my forearms aching as I hand-grated a block of Swiss cheese with a dull box grater that kept slipping on the slick surface. The kitchen smelled of woodsmoke and roasting pork, and my job was to prep the potatoes while she fished out a worn, blue ceramic baking dish from the depths of her bottom cabinet. It was a slow, rhythmic process—peeling, slicing, and layering—that taught me how simple ingredients, when treated with patience, transform into something completely transcendent.
This isn't just another heavy casserole thrown together with canned cream soup. It is a masterclass in building clean, comforting flavors from scratch.
The magic lies in how we manage the potatoes' starch gelatinization. By slicing them thin and baking them slowly in a seasoned roux-based sauce, the starches escape into the liquid, binding the milk and butter into a luxurious, creamy coat that clings to every single slice. If you love classic potato bakes, you might also enjoy our Super Easy Cheesy Scalloped Potatoes.
It is hands down the ultimate comfort food.
When testing this, we tried using pre-shredded cheese, but it got annoying fast because the anti-caking agents prevented a smooth melt. We highly recommend grating your own Swiss cheese—like Cabot or Emmi—directly from the block to ensure it melts into a seamless, gooey blanket. While I often use leftover ham for a quick batch of Ham Salad or a smoky pot of Cajun Ham & Beans, this potato bake is my absolute favorite way to stretch a holiday roast.
For the salt, we always use Diamond Crystal kosher salt (1 teaspoon of Diamond Crystal equals roughly 1/2 teaspoon of standard table salt) to avoid over-salting the already-savory ham.
As the casserole bakes, the kitchen fills with the warm, savory aroma of dried thyme and sharp mustard powder blooming in the hot fat. You will hear the sauce bubbling furiously around the edges of the dish, while the top layer of potatoes browns into a gorgeous, caramelized crust thanks to the Maillard reaction. When you finally plunge a spoon into the center, the potatoes should yield effortlessly, offering no resistance at all.
Ham & Cheese Scalloped Potatoes
Ingredients
- 2 lbs potatoes, peeled
- 1 medium onion, thinly sliced
- 3 cups chopped ham
- 1/4 cup butter
- 1/4 cup flour
- 3 cups milk
- 1 teaspoon salt
- 1/2 teaspoon pepper
- 1/2 teaspoon dried thyme
- 1/2 teaspoon dry mustard powder
- 8 oz swiss cheese, shredded
Directions
- Preheat the oven to 375°F. Coat a 3-quart baking dish with nonstick cooking spray to prevent sticking.
- In a medium saucepan set over medium heat, melt the butter. Whisk in the flour and cook, stirring constantly, for 2 minutes to eliminate the raw flour taste.
- Whisk in the salt, pepper, dried thyme, and dry mustard powder, then slowly pour in the milk while whisking vigorously. Cook for 3 to 5 minutes, stirring continuously, until the mixture thickens into a smooth, pourable sauce (aim for a light cream consistency, not a heavy gravy). Remove from heat.
- Using a sharp chef's knife or a mandoline, slice the peeled potatoes very thinly, aiming for no thicker than 1/8 inch. Arrange a single, overlapping layer of potato slices across the bottom of your prepared baking dish.
- Evenly scatter 1/3 of the chopped ham and 1/3 of the sliced onions over the potato layer.
- Repeat this layering process twice more—potatoes, ham, then onions—finishing with a final, neat layer of potato slices on top.
- Give the warm cream sauce one last whisk. If it has thickened too much while sitting, stir in a splash of milk to loosen it up.
- Pour the sauce evenly over the layered potatoes, ensuring it seeps down into the crevices, then scatter the shredded Swiss cheese uniformly across the top.
- Bake uncovered for 1 hour and 15 minutes. If the Swiss cheese begins to brown too quickly, tent the dish loosely with aluminum foil.
- Remove the foil and bake for an additional 15 to 20 minutes, until the potatoes are completely tender when pierced with a fork and the cheese is bubbly and golden brown.
Notes
Keep these essential kitchen tips in mind to ensure your potato casserole turns out perfectly every single time:
- Salt Conversion: We developed this recipe using Diamond Crystal kosher salt. If you are using Morton's kosher salt or standard table salt, cut the measurement in half (use 1/2 teaspoon) to keep the dish from becoming overly salty.
- Starch Science: Do not rinse or soak the sliced potatoes after cutting. The surface starch is essential for emulsifying the milk and butter into a cohesive sauce during the long bake.
- Burn Prevention: Keep a close eye on the oven during the last 30 minutes. If the cheese is browning too rapidly before the potatoes are tender, tent the baking dish loosely with foil to protect the dairy from scorching.
- Potato Selection: Russet potatoes work best here due to their high starch content, but Yukon Golds offer a lovely buttery texture. Avoid waxy red potatoes, which won't thicken the sauce as effectively.
- Resting Time: Let the casserole rest on the counter for 10 to 15 minutes before slicing. This allows the starch gelatinization to set, making clean, neat portions much easier to scoop up.
Serving Suggestions
Pair this rich, savory casserole with side dishes that offer bright contrast and crisp textures to balance the meal:
- A crisp green salad tossed in a bright lemon vinaigrette provides a sharp, acidic contrast to the rich, creamy layers of the casserole.
- Roasted asparagus spears or charred green beans add a pleasant, snappy texture that cuts through the soft, comforting potatoes.
- Serve with warm, crusty bread like The BEST Bread Machine Italian Bread to wipe down any leftover cream sauce from your plate.
- Balance the salty, savory meal with a light, sweet, and fruity dessert like our popular Grape Salad.
Storage and Reheating
After 24 hours in the fridge, the flavors in this casserole actually deepen as the onions, thyme, and ham continue to infuse the potato starch matrix. Store any leftovers in an airtight container for up to 4 days.
Reheating requires a tad bit of care to prevent the dairy sauce from breaking into an oily mess. Avoid the microwave if you can, as high, uneven heat will cause the butter fats to separate from the milk solids.
Instead, place your desired portion in an oven-safe dish, splash a tablespoon of milk over the top to restore moisture, and cover tightly with foil. Warm it in a 325°F oven for 15 to 20 minutes until heated through.
Freezing is not recommended for this dish. The cellular structure of the potatoes breaks down during freezing, turning them unpleasantly mealy and watery upon thawing.
Ingredient Substitutes
If you need to adapt the recipe based on what is in your pantry, try these simple, tested swaps:
- Swiss Cheese → Gruyère: Swap the Swiss cheese for Gruyère at a 1:1 ratio for a deeper, nuttier flavor profile; reduce the added salt by a pinch as Gruyère is slightly saltier.
- Dried Thyme → Fresh Thyme: Replace 1/2 teaspoon of dried thyme with 1 1/2 teaspoons of finely chopped fresh thyme leaves to add a brighter, more herbal note to the cream sauce.
- Ham → Smoked Sausage: Use 3 cups of sliced smoked sausage instead of ham at a 1:1 ratio; brown the sausage in a pan first to render out excess fat before layering.
- Dry Mustard Powder → Dijon Mustard: Substitute 1/2 teaspoon of dry mustard powder with 1 teaspoon of smooth Dijon mustard, whisking it directly into the warm roux.
There is something deeply satisfying about pulling a bubbling, golden casserole out of a hot oven on a quiet evening. It fills the home with warmth and brings everyone to the table with minimal fuss.
