6 oz. box potato pancake mix
16 oz. sliced Portobello mushrooms
8 oz. container diced red onions
1 cup milk
1 cup shredded sharp cheddar cheese
1 cup shredded Swiss cheese
5 large eggs
Make potato pancake mix according to directions (will require additional eggs). Let sit to thicken. Preheat oven to 350 degrees. Spray a casserole dish with cooking spray. Spread the potatoes along the bottom of the greased dish. Bake for 25 minutes or until lightly browned.
In a large bowl, combine all the other ingredients. Pour on top of the potatoes. Bake for 45 minutes to 1 hour or until bubbly. Serve for brunch, or add garlic bread and a salad for a meat-free dinner. Serves 6-8.