Tuna Scalloped Potatoes - cooking recipe

Ingredients

6 cups baking potatoes, peeled and sliced
1/4 cup yellow mustard
1/2 cup all-purpose flour
3 1/2 cups milk
1 teaspoon salt
1/2 cup condensed cream of mushroom soup
2 (5 ounce) cans tuna, drained
1 1/2 cups thinly sliced onions

Preparation

Bring a large pot of salted water to a boil. Add potatoes and cook until tender but still firm, about 10 minutes; Drain. Preheat oven to 300 degrees F (150 degrees C).
In a saucepan, combine yellow mustard, flour, milk, salt and 1/2 cup of soup. Mix thoroughly and heat until thickened.
Starting with the potatoes, arrange the potatoes, tuna and onions, in alternating layers in a 9x13 inch baking dish. Pour the mustard sauce all over the top.
Bake in a preheated oven for 1 hour or until hot and bubbly.