Crock-Pot Scalloped Potatoes

2 lbs. potatoes (about 6 medium)

1/4 t. pepper

3 T. butter

1 small onion, thinly sliced

1 can cream of mushroom soup - (10 oz.)

1/4 C. flour

1 t. salt

4 slice American cheese

Peel and thinly slice potatoes. Toss slices in 1 cup water and 1/2 teaspoon cream of tartar. Drain.

Put half of sliced potatoes in greased CROCK-POT. Top with half of onion slices, flour, salt and pepper. Add remaining sliced potatoes and onions.

Sprinkle with remaining flour. Add butter and undiluted soup.

Cover and cook on Low 7 to 9 hours. (High: 3 to 4 hours). Add cheese slices 30 minutes before serving.