In a small bowl, add the bacon, tomato, and Hidden Valley® Original Ranch® Avocado Dressing, and mix well to create a salsa. Shape the beef into 4 burgers. Grill the burgers and onion slices for about 5 to 7 minutes on each side or until an internal temperature of 160°F has been reached. Toast the rolls. Place a burger in each roll. Top each burger with 2 tablespoons of the salsa and grilled onions to taste, and serve. Refrigerate any leftovers promptly in a shallow container. Discard any food left out more than 2 hours (or 1 hour if temperatures are above 90°F).