Blue Cheese Scalloped Potatoes

1 (5.5 ounce) package scalloped potatoes
2 tablespoons butter or margarine
2 1/2 cups boiling water
2/3 cup milk
1/3 cup crumbled blue cheese

Preheat oven to 400 degrees F.

Empty potato slices into a 1 1/2-quart casserole. Sprinkle with sauce mix. Stir in butter, water, milk and blue cheese. Bake uncovered for 30 to 35 minutes or until potatoes are tender. Let stand a few minutes before serving.