In a food processor, pulse tuna until the meat is in pieces about the size of a garbanzo bean. Add to a bowl with all of the remaining ingredients except the breadcrumbs. Using your hands, combine ingredients. Add breadcrumbs and mix with hands. Form a ball about the 4 inches in diameter. Press together to form a patty about 3/4 – 1 inch thick. If the patty is too moist, add a little more breadcrumbs. If it’s too dry, add some mayonnaise.