2. Sautee onions in a skillet over medium heat until browned.
3. In a medium bowl, combine onions and mayonnaise until onions are well coated.
4. Transfer onion mixture into 9 x 13 pan and sprinkle shredded cheese over mixture. Bake for approximately 35 minutes are until top is bubbly or light golden brown. Be careful about over baking as the cheese will harden and be difficult to dip crackers in.