In a pot, bring the beef, water, green onion and garlic to a boil over high heat. Reduce the heat to low and simmer uncovered until the beef is tender and the stock has reduced to two-thirds, 30–45 minutes. Remove from the heat.
Remove the beef from the broth and slice thinly. Skim any fat from the surface, then season the broth with the soy sauce and salt. Kee