Combine soup, milk and spices in a bowl. Sauté thinly sliced onion rings in 1 tablespoon butter.
Lightly oil a casserole dish or glass lasagna pan with olive oil.
Arrange potatoes in a single layer in bottom of dish. Drizzle soup mixture over top.
Arrange onions and mushrooms. Sprinkle cheese over each layer.
Continue to layer in this manner until all ingredients are used up.
Bake at 375°F for approximately 1 hour or until potatoes reach desired texture.
For a crispy top layer, uncover during the last 10-15 minutes of cooking time.
Submitted by: Lisa Pustai