1. Cut the onions into thin slices and sauté over medium heat in olive oil, on a hot pan.
2. Sauté until onions turn golden brown, approximately 10-15 minutes.
3. Add salt to taste.
1. Mix mayonnaise with chipotle chilies and salt to taste.
1. Shape the meat into 8 small patties and fry in olive oil at high heat.
2. Season with salt and pepper. Top with cheese and let melt.
3. Dress the buns with the chipotle mayo, top with lettuce, tomato, sautéed onions, and patties.
4. Serve immediately.