If your grill is large enough, you can cook everything at once. Give the hamburgers about a two-minute head start so that everything is ready to come off the grill at the same time.
Heat grill to medium. In a large bowl, place ground chuck and herbs. Season with salt and pepper. Using your hands, mix ingredients together until combined. Form into 6 patties; set aside.
Brush the tomato and onion slices with oil, and season with salt and pepper. Grill the tomato and onion slices until slightly charred on both sides (onion should be tender), 4 to 6 minutes for tomatoes and 6 to 8 minutes for onions. Remove from the grill, and keep warm.
Grill hamburger patties, 3 to 5 minutes per side for medium-rare. When they have reached desired doneness, place cheese on top of each patty. Grill until cheese is slightly melted.
To serve, stack slices of onion and tomato on a serving platter with romaine and endive. Place hamburgers on top.