Cheesy Ham and Potato Casserole with Rich Cream Sauce Step-by-step instructions

Before you start

Before you begin cooking, gather all your kitchen tools and measure out your ingredients to ensure a smooth, stress-free process. Peel the potatoes and dice them into uniform half-inch cubes, placing them in a bowl of cold water if you are prepping ahead to prevent browning.

Dice your cooked ham into matching half-inch pieces. Shred your sharp cheddar cheese from the block and divide it into two equal portions. Preheat your oven to 375°F (190°C) and grease your baking dish so it is ready for assembly.

Instructions

Prep and Assembly

1. 1Prep the Oven and Ingredients
   Preheat the oven to 375°F (190°C). Lightly grease a 9x13-inch glass baking dish with cooking spray or butter. Peel the potatoes and dice them into uniform half-inch cubes. Dice the cooked ham into similar-sized pieces so that every bite of the casserole has a balanced mix of ingredients.
   Look for The oven is preheated and the baking dish is ready.
   Tip Keep potato cubes uniform in size to ensure they cook evenly throughout the casserole.
2. 2Combine with Cream Sauce
   In a large bowl, fold the diced potatoes, diced ham, and half of the shredded cheddar cheese directly into the rich cream sauce until everything is thoroughly coated. Transfer the mixture into the prepared glass baking dish, spreading it out into an even layer with a spatula.
   Look for The potatoes and ham are completely coated in cream sauce and leveled in the dish.
   Tip Gently fold the ingredients to avoid breaking up the diced potatoes.

At the end of this phase, the potatoes, ham, and half of the cheddar cheese are thoroughly folded into the rich cream sauce. The mixture should look completely cohesive, with every piece of potato and ham well-coated. Once transferred to the greased glass baking dish, it should form an even, level layer, ready to go into the preheated oven.

Initial Bake

3. 3Bake Covered
   Cover the baking dish tightly with aluminum foil to trap the steam and help the potatoes cook. Place the dish in the preheated oven and bake for 35 minutes until the potatoes are tender.
   Look for The potatoes should be tender when pierced with a fork before adding the final cheese.
   Tip Tightly sealing the foil ensures the moisture stays inside to cook the potatoes thoroughly.
4. 4Add Cheese and Brown
   Carefully remove the foil, sprinkle the remaining shredded cheddar cheese evenly over the top, and return the dish to the oven uncovered. Bake uncovered for another 10 minutes until the cheese is melted, bubbling, and golden brown in spots.
   Look for The cheese is bubbling and golden, and the sauce has settled.
   Tip Watch the oven closely during the final minutes to prevent the cheese from burning.

At this point, the casserole has spent its time under the foil, and the potatoes should be fork-tender. When you remove the foil, you will see a hot, bubbling cream sauce surrounding the potatoes and ham. The mixture should look cohesive and smell incredibly savory. The freshly sprinkled cheddar cheese on top will begin to melt immediately upon contact with the hot casserole.

Browning and Resting

5. 5Rest and Settle
   Remove the casserole from the oven and place it on a wire rack. Let the dish rest for 10 minutes at room temperature before serving to allow the rich cream sauce to cool and thicken up.
   Look for The intense bubbling will subside and the sauce will set.
   Tip Do not skip the resting time, as the sauce will be too runny if served immediately.

By the end of the final bake and rest, the top of the casserole will sport a beautiful, golden-brown crust of melted cheddar cheese with caramelized, crispy edges.

The intense bubbling will subside during the ten-minute resting period, and you will notice the cream sauce thickening significantly, settling into a rich, velvety glaze that holds the potatoes and ham together perfectly as you scoop it.

Common mistakes

One common mistake is dicing the potatoes too large, which results in hard, undercooked potato bites even after the full baking time has elapsed. Keep them to a uniform half-inch size. Another frequent error is serving the casserole immediately after taking it out of the oven.

The sauce needs time to cool slightly and set; if you scoop into it immediately, the liquid will be runny and pool at the bottom of the dish instead of clinging beautifully to the potatoes.

How to tell it’s done

To determine if the casserole is perfectly done, insert a sharp paring knife or a fork into the center of the dish; it should slide easily through the potato cubes without any resistance.

The cheese on top should be completely melted, bubbling vigorously around the edges, and beautifully browned. Since there are no raw proteins in this recipe, you are primarily testing for the tender texture of the potatoes and the hot, bubbling consistency of the cream sauce.