2 pounds chicken legs or thighs and 1 pound chicken feet go into a pot with 4 liters water. Bring to a boil and skim off scum til mostly clear.
Add 1 bunch of green onions (if making soup out of the stock, 2-4 whites chopped and reserved along with a similar amount of chopped celery and carrot) and 1 tbsp black peppercorns. Cover, reduce to simmer and cook 1 hour.
Remove skin from chicken parts (not the feet) and return to pot, simmering an additional 30 minutes uncovered until chicken easily falls off bone.
Remove chicken pieces, and remove the meat from the bones when cool enough to handle.
Strain remaining stock and discard onions and feet.
If stock is not concentrated enough, return to pot and reduce to desired consistency (typical net out is 2L of liquid.)
Stock can be cooled and frozen from here, or made into soup by simmering reserved onion whites and other vegetables in some stock in a lidded pot until soft before re-adding the chicken and salting to taste.
If adding rice or pasta, precooking it will keep it from absorbing and thickening the broth (or you can add it in place of a reduction but that timing is tricky).