Spray a cold grill rack with Pam. Then place rack on grill. Grill burgers on an uncovered grill directly over medium coals for 7 minutes. Turn and grill 8-11 minutes or till no pink remains. Place 1 tomato slice atop each burger and grill 1 minute more. *********************************************************** Per serving: 290 calories, 23 g protein, 8 g carbohydrates, 18 g fat, 79 mg cholesterol, 441 mg sodium, 351 mg potassium.