This is the sequence of how I made these dumplings: make char siu and leave it to bake in the oven, while char siu is in the oven, mix dough and leave it to proof covered, while dough is proofing, make filings and leave it in the freezer to cool, while filings is in the freezer, weigh dough into 30g each. When weighing is done, wrap filings in dough. Then steam!