Scalloped Potatoes and Ham
This creamy, comforting casserole layers thinly sliced russet potatoes and tender ham in a rich homemade cheese sauce, then bakes until golden and bubbly. Using a roux-based sauce with sharp cheddar and gruyere elevates this classic dish far beyond the canned soup versions.
Equipment
- Mandoline slicer - for thin, even potato slices
- 9x13-inch baking dish - ceramic or glass
- Medium saucepan
- Wooden spoon or silicone spatula
- Whisk
- Box grater or stand mixer with shredding attachment
- Cutting board and sharp knife
- Measuring cups and spoons
- Aluminum foil
- Oven mitts
- Ladle or large spoon - for spreading sauce
Ingredients
- 2.5 lbs russet potatoes - 1.1 kg, peeled and thinly sliced (about 1/8 inch / 3 mm thick)
- 2 cups cooked ham - 300g, diced or cut into small cubes
- 3 tablespoons unsalted butter - 43g
- 3 tablespoons all-purpose flour - 24g
- 2 cups whole milk - 480 ml, warmed
- 1 cup heavy cream - 240 ml
- 1.5 cups sharp cheddar cheese - 170g, freshly shredded, divided
- 0.5 cup gruyere cheese - 57g, freshly shredded (optional but highly recommended)
- 1 teaspoon kosher salt - 5g
- 0.5 teaspoon black pepper - 1g, freshly ground
- 0.5 teaspoon garlic powder - 1g
- 0.25 teaspoon onion powder - 0.5g
- 0.25 teaspoon smoked paprika - 0.5g
- 1 tablespoon fresh thyme leaves - or 1/2 teaspoon dried thyme, optional
- 1 small yellow onion - thinly sliced (optional, adds extra savory depth)
- fresh parsley - chopped, for garnish
Instructions
- Preheat oven to 375°F (190°C). Grease a 9x13 inch baking dish with butter or cooking spray.
- Peel potatoes and slice into 1/8 inch (3 mm) rounds using a mandoline slicer. Place slices in cold water to prevent browning, then drain and pat thoroughly dry.
- Dice ham into 1/2 inch (1.2 cm) pieces. If using onion, slice into thin half-moons.
- Melt butter in a medium saucepan over medium heat. Whisk in flour and cook for 1-2 minutes until golden and nutty. Slowly pour in warmed milk, whisking constantly, then add heavy cream.
- Cook sauce, stirring frequently, until thickened enough to coat the back of a spoon, about 5-7 minutes. Remove from heat and stir in 1 cup cheddar and all gruyere until melted and smooth.
- Season sauce with salt, pepper, garlic powder, onion powder, and smoked paprika. Taste and adjust seasoning as needed.
- Spread a thin layer of sauce in the baking dish. Layer one-third of potatoes, half the ham and onion (if using), and one-third of sauce. Repeat layers, then finish with remaining potatoes and sauce. Sprinkle remaining cheddar on top.
- Cover tightly with foil and bake for 45 minutes. Potatoes should be mostly tender when pierced with a knife.
- Remove foil and bake uncovered for 20-25 minutes until golden and bubbly. For extra browning, broil for 2-3 minutes, watching closely.
- Let the casserole rest for 10-15 minutes before serving. Garnish with fresh parsley and serve warm.
Notes
- Slice potatoes uniformly using a mandoline to ensure even cooking. Uneven slices lead to some potatoes being undercooked while others turn mushy.
- Warm the milk before adding it to the roux to prevent a lumpy sauce. Cold milk hitting a hot roux is the most common cause of sauce failure.
- Always shred your own cheese from a block. Pre-shredded cheese contains anti-caking agents that prevent smooth melting and can leave the sauce grainy.
- Do not skip the resting time after baking. Letting the casserole sit for 10-15 minutes allows the sauce to set so you get clean, intact slices when serving.
- This dish is make-ahead friendly. Assemble the casserole, cover tightly, and refrigerate for up to 24 hours. Add 15 minutes to the covered baking time if baking from cold.
- If your potatoes are still firm after the covered baking time, re-cover and bake for an additional 10 minutes before removing the foil.
- Store leftovers covered in the refrigerator for up to 4 days. Reheat covered with foil at 350°F (175°C) for 20-25 minutes.
- For a lighter version, substitute the heavy cream with additional whole milk. The sauce will be slightly thinner but still delicious.
- Add 1/4 teaspoon of cayenne pepper and 1 teaspoon of Dijon mustard to the sauce for a spicy, tangy variation that cuts through the richness.
- Leftover scalloped potatoes can be frozen for up to 2 months, though the potato texture will soften somewhat. Thaw overnight in the refrigerator before reheating.