Gluten-Free Upside-Down Pizza

Preheat oven to 350 degrees F (175 degrees C). Grease a 9x13-inch baking dish.

Heat a large skillet over medium-high heat. Cook and stir beef and onion in the hot skillet until beef is browned and crumbly 5 to 7 minutes; drain and discard grease. Stir pizza sauce salt and oregano into ground beef mixture.

Spread meat mixture into the prepared baking dish; top with mozzarella cheese.

Whisk flour milk and eggs together in a bowl until well mixed; spread mixture over mozzarella cheese layer. Sprinkle 3-cheese blend over flour mixture.

Bake in the preheated oven until cheese is bubbling and melted about 35 minutes.