Partially freeze beef. Slice beef very thinly across the grain into bite-size strips.
Dissolve beef bouillon granules in boiling water; add soy sauce and sugar.
Add cooking oil; preheat wok over high heat.
Add bok choy, green onions, and celery; stir-fry 2 minutes.
Remove bok choy, green onions, and celery.
Add tofu, bean sprouts, bamboo shoots, mushrooms, and water chestnuts; stir-fry 1 minute.
Remove vegetables. (Add more oil, if necessary.)
Add the beef to hot wok; stir-fry 2 minutes or till meat is just browned.
Stir beef bouillon mixture; stir into beef.
Cook and stir till bubbly.
Stir in vegetables.
Cover and cook for 1 minute or till just heated through.
Serve at once.