Scalloped Potatoes and Ham: The Best Easy Recipe & Common Mistakes

Anyone who’s pulled a scalloped potato casserole out of the oven only to find crunchy centers and a pool of watery sauce knows the frustration. The difference between a perfect, creamy dish and a disappointing one often comes down to a few science-backed steps.

Average cook time: 75-90 minutes ·
Primary cooking method: Baked casserole ·
Key ingredient ratio: 2 lbs potatoes : 1 lb ham ·
Common sauce base: Milk and butter roux ·
Recommended potato type: Russet or Yukon Gold

Five key facts, one pattern: the difference between a creamy casserole and a soupy disaster hinges on potato choice, slice thickness, and heat management.

How to make the best scalloped potatoes and ham?

Step-by-step recipe instructions

• Preheat: Set oven to 350°F (175°C).
• Prepare potatoes: Peel and slice potatoes into 1/8-inch rounds using a mandolin for even thickness (Key To My Lime).
• Par-boil (optional but recommended): Bring a pot of salted water to a boil. Add potato slices and cook for 3-5 minutes until just slightly tender. Drain and set aside (Yellow Bliss Road).
• Make the sauce: In a saucepan over medium heat, melt 3 tablespoons butter. Whisk in 3 tablespoons flour and cook for 1 minute. Gradually whisk in 2 cups whole milk, stirring constantly until thickened (about 3-5 minutes). Season with salt, pepper, and a pinch of nutmeg if desired (Betty Crocker).
• Layer: In a greased 9×13 baking dish, arrange one-third of the potato slices. Top with half the diced ham, then one-third of the sauce. Repeat layers. Finish with remaining potatoes and sauce. If using cheese, sprinkle 1 cup shredded cheddar on top (The Pioneer Woman).
• Bake: Cover with foil and bake for 45 minutes. Remove foil and bake another 15-20 minutes until potatoes are tender and top is golden brown (Adore Foods).
• Rest: Let the casserole sit for at least 15 minutes before serving. This allows the sauce to thicken properly (Spend With Pennies).

Key ingredients and ratios

The foundation of a great scalloped potatoes and ham casserole relies on a specific ratio. For 6-8 servings, use 2 pounds of starchy potatoes (Russet or Yukon Gold), 1-2 cups of diced cooked ham, and 2 cups of whole milk in the sauce (Spend With Pennies). The butter-to-flour ratio for the roux is a standard 1:1 by volume — 3 tablespoons each creates enough body for a 9×13 dish without becoming gluey.

Ham choice matters: leftover roasted ham works best. Avoid pre-sliced deli ham, which can turn rubbery during the long bake. If you are using a saltier cured ham, reduce added salt in the sauce (Adore Foods).

Do you have to boil potatoes before making scalloped potatoes?

Why par-boiling is recommended

• Par-boiling for 3-5 minutes ensures tender centers in a dish that bakes for about 60 minutes total (Yellow Bliss Road).
• It reduces the risk of raw, crunchy potato in the middle layers, a top reader complaint according to Allrecipes.
• Par-boiling also partially gelatinizes the starches, which helps them absorb the sauce during baking.

How to par-boil potato slices

Bring a large pot of salted water to a rolling boil. Add the 1/8-inch potato slices and cook for 3-5 minutes — they should still hold their shape but bend slightly. Drain immediately and spread on a baking sheet to cool. Do not rinse: you want the surface starch to remain, as it helps the sauce cling (Yellow Bliss Road).

Skipping par-boiling is possible if your slices are very thin (1/8 inch or less) and you bake the casserole longer — but the risk of undercooked centers increases. Most test kitchens, including Betty Crocker, rely on a covered bake of sufficient length (45 minutes) to handle thin slices without par-boiling.

The implication: par-boiling is a cheat code for consistency. Skip it only if you have a mandolin to guarantee paper-thin slices and are willing to extend the covered baking time by 15 minutes.

What are some common mistakes to avoid when making scalloped potatoes?

Mistake: Soaking potatoes too long

• Soaking sliced potatoes in cold water removes surface starch, which is exactly what you need to thicken the sauce (Sara Moulton (chef and cookbook author)).
• With less starch in the dish, the milk sauce stays thin and turns watery as the potatoes release their own liquid.
• If you must prep ahead, store sliced, unsoaked potatoes in water for up to 2 hours, then pat very dry before layering.

Mistake: Using wrong potato variety

• Waxy potatoes (red bliss, fingerlings) hold their shape well but do not release starch, which is needed to create a creamy sauce. The result is a watery, separated pan of sauce (Allrecipes).
• High-starch potatoes like Russets are the standard choice — they break down slightly and release starch that emulsifies with the milk, creating that velvety texture (Sara Moulton (chef and cookbook author)).
• Yukon Golds (medium starch) are a good intermediate option if you want some structural integrity plus enough starch for body (The Pioneer Woman).

Mistake: Overcooking the sauce

• Boiling a milk-based sauce on high heat causes the proteins (casein) to clump and the fat to separate — a phenomenon called curdling or splitting (Allrecipes).
• Keep the heat at medium and whisk constantly when adding milk to the roux. If you see bubbles larger than a simmer, reduce the heat immediately.
• A curdled sauce cannot be fixed once it happens. The only remedy is starting a new batch — which is why temperature control is the single most important step in the recipe.

What goes best with ham and scalloped potatoes?

Vegetable side dishes

• Steamed broccoli or green beans add color and a fresh, slightly bitter contrast to the rich, creamy casserole (Spend With Pennies).
• Roasted asparagus (tossed in olive oil, salt, and pepper, then roasted at 400°F for 12-15 minutes) provides a bright, nutty flavor that cuts through the richness.
• Sugar snap peas or a simple sauté of peas and pearl onions add sweetness and visual appeal.

Salads and bread pairings

A crisp green salad with a tangy vinaigrette (lemon or red wine vinegar based) balances the heaviness of the casserole. Avoid creamy dressings, which double down on the richness (Betty Crocker). A side of crusty bread or warm dinner rolls is traditional — not because the casserole needs carbs, but because the bread soaks up any extra sauce left on the plate.

What this means for your menu: ham and scalloped potatoes is a rich, one-dish casserole. The best accompaniments are simple, acidic, and green — not another creamy or starchy side.

What liquid works best for scalloped potatoes?

The liquid you choose directly determines the casserole’s richness and foolproofness. Each option trades off convenience for texture.

How liquid choice affects texture

Whole milk is the standard for a reason: it contains enough fat (3.25%) to prevent curdling during baking while allowing the potatoes’ own starch to contribute to the sauce’s body. Heavy cream makes the dish foolproof — the high fat content resists curdling and yields a velvety result — but it also adds significant calories and fat. Broth creates a thinner, less creamy sauce that allows the ham’s saltiness to shine through, but the dish will never achieve that classic lush texture (Allrecipes).

The pattern: your liquid choice is a trade-off between richness and ease. Whole milk offers the best balance for most home cooks — it is forgiving enough for standard techniques but rich enough to deliver a creamy casserole.

“Soaking sliced potatoes in water removes the starch you need for a creamy sauce. For scalloped potatoes, don’t soak — the surface starch is your friend.”

— King Arthur Baking Company (flour and baking authority)

“I prefer Yukon Gold potatoes for scalloped potatoes because they hold up a little better than Russets while still giving you enough starch to thicken the sauce.”

— The Pioneer Woman (food blog)

For a home cook preparing a holiday dinner or a Sunday supper, the choice between technique shortcuts and proper method is clear: invest the extra 10 minutes in par-boiling and use a starchy potato, or risk a casserole that separates and disappoints. No amount of cheese on top can fix a watery, curdled base.

Related reading: common mistakes that cause undercooked potatoes · parboiling improves scalloped potatoes and ham

For a classic take on the dish without ham, the traditional scalloped potatoes recipe provides a foolproof guide to creamy, tender layers.

Frequently asked questions