Wash and soak mushrooms in warm water for 30 minutes; shred.
Wash and soak dried bamboo shoots in warm water for 1 hour; shred in 1" pieces. Slice pork butt into 1" matchsticks. Wash and trim green onion, shred on the bias into 1" pieces.
Soak rice stick noodle in warm water until soft.
In sauce pan, heat broth. When it reaches gentle boil, add pork, mushrooms, bamboo shoots, soy sauce and sugar; simmer 10 minutes. Add soaked rice stick noodles; simmer for another 10 minutes.
A minute before removing from heat, add vinegar and sesame oil; stir.
Remove to serving bowl; garnish with shredded green onions. Serve.