Cook onion and garlic in oil in 2- to 3-quart saucepan over medium heat until onion is tender. Add broth, rice, soy sauce and pepper flakes. Bring to a boil; stir once or twice. Cover and simmer 15 minutes or until rice is tender and liquid is absorbed.
Stir green onions, red pepper and sesame seeds into cooked rice; cover and let stand 5 minutes. Fluff with fork