In a pot over medium heat, fry the onions for about 1 minute before adding the garlic. Fry for a further 1 minute. Add the minced pork and fry briefly until slightly browned. Add the chicken stock, Hoisin sauce and pepper before simmering over low heat for about 1 hour. The mixture should be dry and thick by then. Add the chopped chives and reserve. Preheat the oven to 180 degree Celsius.
Cut small rectangles from the pastry and fill a small dollop of meat mixture on one half of the pastry.
Brush the sides with egg before folding the other half and sealing shut by pressing the edges with a small fork.
Place the mini puffs on a baking tray lined with parchment paper and brush thinly with some additional eggwash and sprinkle some white sesame seeds.
Bake for 12-15 minutes until golden. Allow to cool slightly before serving.