Ingredients

• in a small bowl, combine the mayonnaise, mustard, cumin, lemon juice, salt and pepper; cover and refrigerate until serving.
• grill green pepper, covered, over medium heat until skin blisters, about 6 minutes. with tongs, rotate pepper a quarter turn. grill and rotate until all sides are blackened. immediately place pepper in a bowl; cover and let stand for 15-20 minutes.
• meanwhile, shape beef into two patties. grill, uncovered, over medium-hot heat for 7-9 minutes on each side or until a meat thermometer reads 160 degrees f.
• peel off and discard charred skin from green pepper; remove stem and seeds. cut pepper in half. top each patty with green pepper and cheese; grill 1 minute longer or until cheese is melted.
• grill buns, cut side down, for 1-2 minutes or until toasted. spread bun bottoms with mayonnaise mixture; top with burgers, tomato, onion and lettuce. replace bun tops.