In a large bowl, mix tuna, egg, bread crumbs, green onions, and garlic. Blend soy sauce, teriyaki sauce, ketchup, sesame oil, and pepper into the mixture. Form the mixture into about 6 patties approximately 1 inch thick. Lightly sprinkle each patty on all sides with cornmeal.
Heat oil in a medium skillet over medium heat. Fry each patty about 5 minutes on each side, until golden brown.