Equipment Needed
- 6-quart or larger slow cooker (Crockpot)
- Mandoline slicer or sharp knife and cutting board (for even potatoes)
- Large mixing bowl
- Measuring cups and spoons
- Small bowl for mixing sauce
- Non-stick cooking spray
Step-by-Step Instructions
My process starts with the most important prep step: slicing the potatoes. I’ve learned that uniformity is key here. I use a mandoline slicer on the second-thickest setting to get even, 1/8-inch slices. This ensures they all cook at the same rate. If I’m using a knife, I take my time to keep them consistent. Uneven slices mean some will be mushy while others are still crunchy. I place all the slices in a large bowl of cold water as I go to prevent browning and to rinse off some excess starch, which helps the sauce thicken nicely later.
While the potatoes soak, I prepare the creamy sauce that will bind everything together. In a medium bowl, I whisk together the condensed soup, sour cream, milk, melted butter, garlic powder, onion powder, and black pepper until it’s completely smooth. This sauce is the flavor powerhouse, and using full-fat sour cream here makes a huge difference in creaminess. I then drain the potato slices and pat them very dry with clean kitchen towels or paper towels. This is a step I skipped once, and the extra water made the final casserole a bit soupy. Drying them is crucial.
Now for the satisfying layering process. I spray my slow cooker insert generously with non-stick spray. I start by spreading a thin layer of the sauce on the very bottom. Then, I create my first layer: one-third of the potato slices, half of the diced ham, half of the sliced onions, and one-third of the shredded cheese. I spoon one-third of the remaining sauce over the top. I repeat these layers one more time. For the final layer, I add the last third of the potatoes, pour the remaining sauce over the top, and finish with the last third of the cheese. I gently press everything down with the back of my spoon. (See the next page below to continue…)