Slow Cooker Scalloped Potatoes

Ingredients

• 7 to 9 medium potatoes, thinly sliced, about 2 pounds or 4 to 5 cups
• 1 cup cold water
• ½ teaspoon cream of tartar
• 3 tablespoons butter
• 1 medium onion, thinly sliced
• ¼ cup all-purpose flour
• 1 teaspoon salt
• ¼ teaspoon ground black pepper
• 1 can (10¾ ounces) condensed cream of mushroom soup
• 4 ounces American cheese, slices or shredded

Instructions

1. Toss potato slices in 1 cup water and ½ teaspoon cream of tartar, then drain.
2. Put half of sliced potatoes in a buttered or greased 3½ to 4-quart slow cooker.
3. Top with half of onion slices, half of the flour, half of the salt and half of the pepper.
4. Dot with half of the butter.
5. Repeat layers; dot with remaining butter.
6. Spoon soup over the top.
7. Cover and cook on low 7 to 9 hours, or 3 to 4 hours on high.
8. Add cheese about 30 minutes before serving.