Salt and Pepper to taste Divide ground beef into 8 equal portions; shape each into 4 inch diameter patties. Place equal amounts of cheese in center of 4 patties. Top with remaining 4 patties; press edges together to seal securely. Place patties on grid over medium coals. Grill 10 to 12 minutes or to desired doneness,turning once. Season with salt and pepper to taste. Toast buns on grill on minute, if desired. Arrange one lettuce leaf on each bun bottom; top each with one burger and one tomato slice. Cover with bun tops. Two ounces Monterey Jack cheese and 1/4 cup canned chopped green chillies, drained, may be substituted for Monterey Jack Cheese with Jalapeno peppers.