Ham & Cheese Scalloped Potatoes

Ingredients

• 907 g (2 lb)potatoes, peeled
• 1 mediumonion, thinly sliced
• 710 ml (3 cups)chopped ham
• 60 ml (¼ cup)butter
• 30 g (¼ cup)plain flour
• 710 ml (3 cups)milk
• 1 teaspoonsalt
• ½ teaspoonpepper
• ½ teaspoondried thyme
• ½ teaspoondry mustard powder
• 227 g (8 oz)Swiss cheese, grated

Instructions

1. 1

   Heat the oven

   Preheat the oven to 190°C (375°F). Coat a 3-quart baking dish with cooking spray.

2. 2

   Make the roux

   Melt the butter in a saucepan over a medium heat, then whisk in the flour. Cook, whisking, for 2 minutes.

3. 3

   Thicken the sauce

   Add the salt, pepper, thyme and mustard powder, then whisk in the milk. Cook and whisk for about 3–5 minutes, until smooth and thickened to a sauce consistency rather than a thick gravy. Take the pan off the heat.

4. 4

   Slice the potatoes

   Cut the potatoes into very thin slices, no thicker than 3 mm (⅛ inch). Arrange a single layer in the prepared baking dish.

5. 5

   Add ham and onion

   Scatter a third of the ham and a third of the onion over the potatoes.

6. 6

   Repeat the layers

   Add another single layer of potatoes, then repeat the ham, onion and potato layers twice more, finishing with potatoes on top.

7. 7

   Check the sauce

   Whisk the sauce again. If it has thickened too much, whisk in a little milk so it is sauce-like rather than thick like gravy.

8. 8

   Top with cheese

   Pour the sauce evenly over the layered ingredients, then scatter the cheese over the top.

9. 9

   Bake the casserole

   Bake uncovered for 1 hour 15 minutes. When the cheese begins to brown, cover the dish loosely with foil.

10. 10

    Finish until tender

    Remove the foil and bake for a further 15–20 minutes, until the cheese is golden and the potatoes are tender.

What are scalloped potatoes?

Scalloped potatoes are a baked casserole of thinly sliced potatoes cooked in a creamy sauce. The dish is associated with American home cooking, where it is often served as a substantial side or a simple main.

This version adds chopped ham and Swiss cheese to the classic potato-and-sauce base. The ham brings savoury flavour, while the cheese forms a browned top as the potatoes soften underneath.

Nutrition and macros by portion

The nutrition label shows one serving as written: 420 calories, 29g protein, 40g carbs, 17g fat.

The potatoes and flour provide most of the carbohydrates, while the butter, milk and Swiss cheese contribute much of the fat. Ham and cheese provide most of the protein, and both can also add substantial sodium. Serve a portion with a generous helping of vegetables or salad for a more balanced plate.

The potatoes and layers

Thin slices: Cut the potatoes no thicker than 3 mm so they cook through in the stated baking time. A mandoline can make the slices even, but take care when using one.

Even layers: Spread each layer across the dish rather than piling ingredients in the centre. Dividing the ham and onion into thirds helps distribute them through the casserole.

Getting the sauce right

Cook the roux: Whisking the flour into melted butter and cooking it for 2 minutes helps make a smooth base for the milk. Keep whisking as the sauce thickens so it does not form lumps.

Sauce consistency: The mixture should coat the ingredients but still pour easily; it should not be as thick as gravy. If it firms up while you assemble the layers, whisk in a little milk before pouring.

How to judge doneness

Potato test: After the full bake, pierce the centre with a thin knife. The potatoes should feel tender rather than firm or crunchy.

Golden top: Cover the dish loosely with foil once the cheese starts to brown, then uncover it for the final 15–20 minutes. This protects the top while the potatoes finish cooking and lets the cheese turn golden.

Timing and resting

The method calls for 1 hour 15 minutes of baking, followed by another 15–20 minutes uncovered. Begin checking for tenderness at the end of that range, as slice thickness and the dish can affect how quickly the potatoes cook.

Let the casserole settle briefly after taking it from the oven. This makes it easier to serve neat portions while the sauce remains hot.

What to serve alongside

Fresh contrast: Serve with a crisp green salad or a simple vegetable such as green beans to balance the richness of the creamy potatoes, ham and cheese.

For a larger meal, pair it with roast vegetables. Since the casserole is filling, a lighter side can keep the plate from feeling too heavy.

Recipe notes & tips

• Slice the potatoes evenly so they cook at a similar rate.
• Whisk the milk in gradually to help keep the sauce smooth.
• Taste the sauce before adding extra salt, as ham and cheese can be salty.
• Keep the foil loose so it does not press into the cheese.
• Use a thin knife to check the potatoes in the centre of the dish.

Variations

• Use another cheese: Replace the Swiss with a similar amount of grated Cheddar for a stronger flavour.
• Add garlic: Stir a little finely minced garlic into the butter before whisking in the flour.
• Include vegetables: Add a layer of cooked broccoli or peas between the potato layers.
• Change the herbs: Swap the dried thyme for dried rosemary or parsley.
• Make it meat-free: Leave out the ham and add sliced mushrooms or extra vegetables between the layers.

Common mistakes to avoid

• Thick potato slices: They may stay firm in the centre; cut them no thicker than 3 mm.
• Lumpy sauce: Add the milk while whisking and keep stirring as it thickens.
• Over-thick sauce: Whisk in a little milk before pouring so it can spread through the layers.
• Cheese browning too soon: Cover the dish loosely with foil once the top starts to brown.
• Uneven layers: Spread the potatoes, ham and onion across the dish instead of leaving them in clumps.

How to store

Refrigerate leftovers in a covered container for up to 3 days. Reheat portions in the oven or microwave until piping hot; add a small splash of milk if the sauce has thickened.

Frequently asked questions