Directions. Butter a 1 quart sized crock pot. Layer the potato slices and onion rings in the crock, lightly seasoning with salt and pepper every few layers. In a medium-size saucepan, melt butter over medium heat. Gradually stir in milk. Cook until mixture has thickened.
Butter a 2 quart Casserole dish for oven baking or if small enough to fit in crockpot. Otherwise, use the crockpot crock. Layer 1/2 of the potatoes into the bottom of the prepared casserole dish. Sprinkle Salt, Pepper, and onion powder and top with remaining potatoes.