melted. stir after 1 minute and each 30 seconds there after. if you do not have a microwave: in moderately heated saucepan add 1/2 of the butter and all of the onions. cook until tender, stir constantly. add pepper, 1/2 of milk, rest of butter and/or cheese. cook until butter and/or cheese is melted, stir constantly. pour contents of saucepan in 4 cup measuring cup. if the measuring cup contains less than 4 cups add milk until 4 cups is reached. in a 9 x 13 x 2 inch pan, cover bottom with layer of potato slices. cover potatoes with sauce. repeat process until potatoes are used up. if potatoes 