In a skillet, brown beef; drain and set aside. In a small bowl, combine flour, salt, pepper, Italian seasoning, eggs and milk; beat until smooth. Pour batter into a greased and floured 12-in. or 14-in. pizza pan. Spoon beef, onion and mushrooms over batter.
Bake at 425° for 25-30 minutes. Remove from oven. Top with pizza sauce and top with mozzarella cheese. Return to oven and bake 10-15 minutes longer.