In a 5 quart heavy bottomed pot simmer the soy sauce, brown sugar, shaoxing wine (if using) cinnamon stick and ginger until the sauce becomes thick and sticky. The mixture will bubble up so watch it carefully.
Remove any excess fat from the chicken thighs
In a separate skillet, brown the chicken thighs for 5 minutes per side (do this in batches)
Add the browned chicken thighs to the soy sauce/barbecue sauce mixture and let simmer, stirring for 5 minutes or until the chicken is fully cooked.
SERVE OVER RICE WITH GREEN BEANS OR BROCCOLI OR ...
CONTINUE WITH THESE DIRECTIONS TO MAKE STEAMED BUN FILLING
Chill the chicken thighs in the refrigerator
Chop the cooled chicken thighs into 1/4 inch pieces.
Stir in chopped scallions, barbecue sauce and Sriracha
Fill the bun dough