Cut beef into very thin strips. In a bowl, combine beef with soy sauce. (I added some crushed red pepper -- love the spice).
In a large saucepan over high heat, bring stock, ginger and garlic to a boil. Add vermicelli; boil for 2 minutes or until softened. Add beef, carrots and cabbage.
Return to a boil; cook for another 2 minutes. Add bean sprouts and cook for 1 minute or until heated through.
Ladle into bowls; garnish with cilantro and chopped green onions. Drizzle with sesame oil, if desired.