Mix soy sauce, Worcestershire sauce, and garlic in a resealable plastic bag. Add cubed beef and seal bag. Lay flat in the refrigerator for a minimum of 4 hours, turning occasionally.
Remove beef from the marinade and pat dry with paper towels.
Pour vegetable broth into a fondue pot and heat to 225 degrees F (105 degrees C). Add wine and green onions to the simmering broth. Use fondue forks to dip beef cubes into the broth until cooked, 1 to 2 minutes per forkful.
