This Korean beef and rice dish features marinated flank steak, green beans and carrot, stir fried, and served over steamed rice and sprinkled with sesame seeds .If you can't find toasted sesame seed, stir regular sesame seed in a frying pan over low heat until golden, 1 minute.
Rinse beef, pat dry, and cut across the grain into 1/8-inch-thick slices about 3 inches long. In a small bowl, mix beef with 1/4 cup Korean marinade.
Remove and discard bean stem ends and strings. Cut beans diagonally in 3-inch lengths. Cut carrot into matchstick-size pieces about 3 inches long.
In a 14-inch wok or 12-inch frying pan over high heat, mix 1/2 cup water, beans, and carrot. Cover and stir occasionally just until tender to bite, about 3 minutes. Drain; immerse in cold water. Drain when cool. In a bowl, mix with vinegar, sesame oil, sugar, and salt to taste.
Place wok over high heat; when hot, add salad oil. Add beef with liquid in bowl; stir until meat is no longer pink, about 2 minutes. Add remaining marinade and broth to pan; stir until boiling.
Scoop rice into bowls; add beef and sauce, then vegetables and seasonings. Sprinkle with onions and sesame seed.