In a large nonstick skillet over medium heat, cook the bacon until crisp, about 5 minutes. Transfer bacon to a paper-towel-lined plate. Wipe the skillet clean, and return to medium heat. Heat 2 tablespoons olive oil then add the onions. Cover and cook, stirring occasionally, until onions caramelize, about 15 minutes. Stir in 1 tablespoon chipotle chile sauce, remove from the heat and let stand until cool. Wipe the skillet clean and set aside.
In a large bowl, mix together the beef with 1/3 caramelized onions mixture, 2 teaspoons chipotle chile sauce and 1 teaspoon cumin. Form the mixture into 6 patties. Sprinkle both sides of each patty with the remaining 2 teaspoons cumin.
Preheat the broiler. In the same skillet, heat the remaining 1 tablespoon olive oil over medium heat. Add the patties and cook for 4 to 5 minutes on each side for medium. Meanwhile, in a small saucepan over low heat, combine the garlic-and-herb and blue cheese and warm until it has a soft, spreadable consistency. Cover and remove from heat. Place the rolls on a broiler pan cut side up and broil until lightly toasted.
Spread a generous amount of the warm cheese spread on the toasted side of each roll bottom. Top with the lettuce slice, a patty, caramelized onions, bacon and set the roll top into place.