In a bowl, use the back of a spoon or a fork to smash the roasted garlic cloves into a paste (this works best if they are still hot or room temperature). Stir in the mayonnaise, season with salt and pepper and set aside.
Preheat the grill.
In a wide sauté pan, place the sliced onions and oil over medium-low heat. Stirring regularly, cook for 30 minutes or until the onions are deeply caramelized. Set aside.
While the onions caramelize, gently work the Worcestershire sauce into the ground beef and form the beef into four ⅓ pound patties that are slightly wider than the buns you purchased. Generously sprinkle both sides of the patties with salt and pepper and set aside.
Grill your burgers, flipping at least once, until the burger reaches your desired level of doneness, or an internal temperature 160°F. Remove from the grill and let rest for 5 minutes.
While the burgers rest, toast the buns on the grill slightly then slather both halves with the roasted garlic aioli. Place the cambozola slices on the bottom bun and top with the burger, optional lettuce or arugula, caramelized onions and the top bun. Serve.
When adding the Worcestershire sauce, be careful not to overwork the burgers. If you do, they will become tough when cooked.Make sure to put the cheese on the bun, not on the burger. Because the cambozola is so soft, it will melt right off of the burger if placed on top.