Melt butter in a skillet over medium-low heat, then cook onions until soft and golden. This step smells like heaven and sets the stage for the creamy sauce. Stir in the flour, toast it for a couple of minutes, and whisk in the milk. Cook for another minute or so until the sauce thickens. Add salt and pepper.

This is where the magic happens. Spray your crock pot with nonstick spray, then add half the potatoes, ham, and cheese. Pour over half the sauce, and repeat with the rest. It’s like making a cheesy, potato-y ham lasagna—what’s not to love?

Cover the crock pot with a double layer of paper towels (this prevents moisture from dripping back on the scalloped potatoes and keeps them from getting watery), slap the lid on, and let it cook.

The sweet spot for potatoes sliced ⅛ inch thick is three to four hours on high. However, all crock pots and slow cookers cook differently, and potatoes that are thicker or thinner than ⅛ inch may take more or less time.

Be sure to test your potatoes with a fork before digging in. The fork should slide through the potato slices easily.