Quinoa adds texture and earthiness to this lean beef burger. Made in a similar way to meatloaf, this patty substitutes an ancient grain for bread crumbs.
Combine ground beef, quinoa, egg and Montreal steak seasoning in large bowl, mixing lightly but thoroughly. Lightly shape into four 1/2-inch patties.
Place patties in center of grid over medium, ash-covered coals. Grill, covered, 8 to 10 minutes (over medium heat on preheated gas grill, covered, 7 to 9 minutes) until instant-read thermometer inserted horizontally into center registers 160°F, turning occasionally. Place burgers on bottom halves of buns; top with tomato slices and lettuce. Close sandwiches.