Upside-Down Pizza

I got the recipe from Robin Miller, and adapted it a bit to suit my family's taste. It was oh-so-good, and my whole family gobbled it up! I'm putting the recipe with the "toppings" we used, but feel free to substitute your favorites.

1 lb sausage (I used sage since we don't like Italian)
1 medium onion, chopped
8 oz mushrooms, sliced
1 cup pasta sauce
1 cup pizza sauce
16 oz mozzarella cheese, shredded
2 eggs
1 cup milk
1 tbsp olive oil
1 cup all-purpose flour
1/2 tsp salt
1/4 cup parmesan, grated

Preheat oven to 400 degrees.

Heat large skillet over medium heat, adding a bit of olive oil if needed to cook sausage. Add sausage and cook until browned and cooked through, breaking up the meat as it cooks with a wooden spoon. Add the onion halfway through cooking, then add mushrooms and cook another 2 minutes, until soft. Add pasta sauce and pizza sauce and bring to a simmer, about 2 minutes. Remove from heat and transfer sauce to the bottom of a 13x9-inch baking dish. Top with mozzarella cheese.

In a medium bowl, whisk together eggs, milk, and oil until blended. Whisk in flour and salt until well blended. Pour mixture over sauce in pan. Sprinkle with parmesan. Bake 25 minutes, or until golden brown. Let stand for 5 minutes before serving.