To make a liter of chicken stock:
4 chicken legs and a 1.5 or so pounds of chicken feet go into a pot with 4 liters water. Bring to a boil, reduce to simmer, and skim off scum til mostly clear.
Add 1 bunch of green onions and a smashed knob of ginger. Simmer uncovered as low as you can until liquid is reduced to desired richness (approximately a liter, after approximately 90 minutes). strain.
If under a liter, top up with water to a liter.Stock can be cooled and frozen from here, or made straight into a soup.