A lot depends on how many you are hoping to feed. I generally make stock from a whole carcass which is left from a meal and add a few chunks of leftover chicken. If you are wanting to start from scratch then use at least a couple of chicken legs or a few drumsticks - you need the bone for flavour. Cover with water, bring to the boil with a bay leaf, a few peppercorns and a whole onion and simmer until the meat falls from the bone - about 45 minutes. Remove the legs from the pan, skin and take all the meat form the bones. Season the stock at this staghe anmd if it isn't hearty enough, add a stock cube - chicken or vegetable. Chop lots of different veg very small - leeks, carrots, swede, red pepper,celery, potato (whatever you have in the fridge) - and add to the hot stock. Bring back to the boil and simmer for 20 minutes until all pieces are soft. Return meat to the pan. Good served with a swirl of cream or yogurt.