Heat the chicken stock, add the agar agar flakes and stir over low heat until they dissolve. Chill until set.
Slightly smash the ginger with the blade of a broad knife to bring out the flavour. Place ginger and spring onion in 180ml warm water. Rub with fingers to extract the flavour - the water should turn slightly green. Sieve and let cool.
Mix in chicken or pork mince, sugar, soy sauce, cooking wine, sesame oil, black pepper and stir well. Gradually mix in the cooled ginger and spring onion water and stir well. Finely dice the set agar and add to the mixture. Stir well; cover and chill in the fridge for at least 4 hours.
Place flour in a large bowl, stir in the oil and 150ml water gradually. Combine and knead to form a smooth dough. Cover with cling film and let stand for 10 minutes.
Cut dough into pieces of 10g each. Roll into balls and flatten into rounds. Leave them a bit thicker in the centre to hold the stuffing. Spoon the mixture in the centre of each, draw up the sides to form a bag shape; twist to seal. Place in a bamboo steamer and steam over high heat for about 10 or 15 minutes or until cooked. Serve with shredded ginger in dark vinegar.
Add more or less water to the dough according to the humidity. The right amount of water makes the perfect buns. Practice makes perfect!
This is a vegetarian thickening agent made from seaweed. You can find it online or at Asian supermarkets.