Potatoes Au Gratin - cooking recipe

Ingredients

5 to 6 medium potatoes, thinly sliced
salt and pepper
1 can Cheddar cheese soup
1 medium onion
margarine
flour
Parmesan cheese

Preparation

In a 9 x 9 x 2-inch dish, arrange by layer the first 6 ingredients.
Repeat layers until dish is filled.
Put Parmesan cheese on top layer.
Fill dish half way with milk.
Cook, uncovered, for 45 minutes to 1 hour at 400\u00b0 or until brown.