Creamy Scalloped Potatoes - cooking recipe

Ingredients

2 lb. potatoes (about 6)
1 small onion, thinly sliced
1/4 c. flour
1 tsp. salt
1/4 tsp. pepper
2 Tbsp. butter
1 (10 3/4 oz.) can cream of mushroom soup
4 slices American cheese

Preparation

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