Prepare a medium-high gas or charcoal grill fire.
Mix the mayonnaise, chili sauce, 2 tsp. of the barbecue sauce, sweet pickle relish, and Worcestershire sauce in a small bowl. Set aside.
In a medium bowl, use your hands to gently mix the bison with the remaining 2 tsp. barbecue sauce, 1 1/4 tsp. salt, and 3/4 tsp. pepper. Form into four 1/2- to3/4-inch-thick patties.
Lightly oil the grill grate and place the patties on the grate. Cover and grill for 4 to 5 minutes. Flip the burgers, cover, and cook to desired doneness, about 5 minutes for medium (130°F to 135°F on an instant-read thermometer).
While the burgers cook, toast the rolls on the grill. Spread some of the dressing on each half of the roll and arrange a lettuce leaf and a slice or two of tomato on the top halves. When the burgers are done, put them on the bottom halves. Assemble the sandwiches, cut in half if you like, and serve.
Serve with Grilled Corn on the Cob and a colorful Summer Bean Confetti Salad with Pickled Red Onion Vinaigrette.
nutrition information (per serving):
Photo: Scott Phillips