Directions

1. Coat grill rack with nonstick cooking spray. Preheat grill to medium (300°F to 350°F). For the sauce, in a small bowl combine mayonnaise, ketchup, relish, 1/2 teaspoon of the mustard, and chipotle powder. Set aside.
2. In a medium bowl combine ground beef, remaining 2 teaspoons mustard, Worcestershire, and salt and pepper to taste; mix well. Form into 4 patties about 1/2-inch thick.
3. Place patties on grill. Grill, covered, 4 to 5 minutes per side or to desired doneness. During the last 2 minutes of grilling, top each patty with 1 cheese slice; grill until melted. Remove from grill.
4. Place buns, cut side down, on grill. Grill until lightly toasted. Remove from grill. Spread sauce on cut sides of buns. Place burgers in buns, top with lettuce and tomato, and serve.