- Coat grill rack with nonstick cooking spray. Preheat grill to medium (300°F–350°F). For the sauce, in a small bowl combine mayonnaise, ketchup, relish, 1/2 teaspoon of the mustard, plus chipotle powder. Set aside.
- 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.
- Grill, covered, 4–5 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.
- Place buns, cut side down, on grill. Grill until lightly toasted. Spread sauce on cut sides of buns. Place burgers in buns, top with lettuce and tomato, and serve.
Per serving: 470 calories, 25g fat, 11g saturated fat, 100mg cholesterol, 690mg sodium, 26g carbohydrate, 1g fiber, 6g sugars, 32g protein