Chinese BBQ Pork Buns

2 tablespoons oil
1/2 cup finely chopped shallots or red onion
2 tablespoons sugar
1 ½ tablespoons soy sauce
2 tablespoons oyster sauce
1 ½ tablespoon sesame oil
1 tablespoon dark soy sauce
¾ cup chicken stock
3 tablespoons flour
2 cups diced Chinese roast pork (cha siu)

While that’s happening, make the meat filling. Heat 2 tablespoons oil in a wok over medium high heat. Add the onion and stir-fry for 2 minutes. Add the sugar, soy sauce, oyster sauce, sesame oil, and dark soy. Stir and cook until it starts to bubble up. Add the chicken stock and flour. Reduce the heat to medium low and cook, stirring, for a couple minutes until thickened. Remove from the heat and stir in the roast pork. Set aside to cool.