In a large bowl, thoroughly mix the ground beef, chorizo, adobo seasoning, and grated onion.
Form into six patties.
Refrigerate for at least 30 minutes, making them firm.
Heat the olive oil in a skillet on medium-high heat.
Add the sliced onions and season with salt and pepper to taste.
Add the jalapeno and brown sugar.
Sauté for 15 minutes or until the onions are caramelized and soft. Set aside.
Drain the roasted red peppers.
Add the mayonnaise, and season with salt and pepper.
Puree the mayonnaise and roasted red peppers until well combined and the mixture is creamy.
Preheat an outdoor grill to high heat. Grill the burger patties until cooked to desired doneness.
Spread one tablespoon of the red pepper mayonnaise on both sides of the rolls.
Lay a burger on the bottom halves, and top with caramelized onions and cheese slices. Serve.