Proportions for 10-12 servings:
- 2 large onions (or 4-5 regular size)
- 2 thumb lengths fresh ginger
- 3-4 cloves garlic
- Green chillies to taste
- 4 tins tomatoes
- 2-3 tbsp salt
- 3 tbsp garam masala (get it unbranded from an asian store, not a supermarket brand - the latter don't taste of very much and come in tiny amounts for the same price as half-kilo bags from asian stores).
- 2 tbsp ground cumin
- 1 tbsp ground coriander seed
- 1-2 teaspoons turmeric (careful! - it stains!)
- 1.5kg chicken on the bone. Don't make it all breast. Half breasts half thighs works well, as does all thighs (and thighs are cheap), as does getting 2-3 entire small chickens, skinning them and chopping them into eighths.
- Fresh coriander leaves - either a large bunch from an asian store, or 3-4 of the tiny packets you get in supermarkets. The former is much cheaper but comes complete with roots which need trimming off and clods of earth which need to be washed off, so is much more fuss.
(warning: you need a seriously large pan for the amounts above. I use a large cauldron. You could use several pans, though, or reduce the amounts of ingredients while maintaining the proportions).
Peel and finely chop the onions, ginger and garlic; also finely chop chillies.
Melt some ghee or vegetable oil in a very large pan. Put the onions, ginger, garlic and chillies in, stir and cover with lid. Stir once a minute or so until onions start turning translucent (4-5 minutes).
Stir in the tomatoes and salt and turn the heat up. Once they start bubbling, stir in the garam masala, cumin, coriander seed and turmeric. Let it bubble for 4-5 minutes, stirring frequently.
Separate any skin from the chicken, and put it in the pan. You don't need to chop it (well, unless you got entire chickens rather than breasts/thighs). I like skin, so I put that in too. Give it a good stir and leave to simmer for at least 40-45 minutes but the longer the nicer up to three hours or so, stirring every so often so that it doesn't stick to the bottom, until the liquid goes dark and there is a layer of transparent liquid at the top, with a few grease spots.
While you are waiting, prepare the fresh coriander. If you got it from a supermarket, wash well and chop. If you got it from an asian store, remove the large clods of earth, individually take the leaves off the stalks (this takes ages - get someone to help, if you can), discard the stalks, wash the leaves well - discarding any yellow or brown ones - and chop. Also start the rice going about 20 minutes before the end.
Stir in the coriander just before serving. You can keep it in the fridge for at most three days, but it freezes very well.
Notes from experience:
100 portions of this takes around two man hours from turning up with bags of product to having the meat simmering (using a food processor for the onions, garlic and ginger; it'll take longer by hand, natch). You'll want the simmer stage for at least an hour to ensure everything is sufficiently heated through for safety (and ideally use a thermometer to check core temperature, natch), but ideally 3-4 hours to properly soften the meat so it falls off the bone. The proportions above that work for a dozen portions do not quite scale correctly to 100; the result is too liquid. Having performed several experiments, ~10% more onion and ~15-20% less tomato than suggested above seems to work best.
You can prepare a vegetarian alternative by splitting off a portion of the base just before adding the meat, then mixing in vegetables; experiment and post results here! I have attempted cauliflower, potato, carrot, swede... what works very well is 2 carrots, 1 potato, 1/2 small swede, 100g okra, two mugs soaked yellow lentils for ~8 vegetarian portions. You'll need to add quite a lot of extra liquid to the vegetarian version - hot water or vegetable stock, perhaps enough to double the volume. The vegetables take 40-50 minutes of simmering to cook, so if you're aiming for a 4 hour simmer on the meat you'll want to cool the vegetarian portion of base and keep it refrigerated until an hour before serving time; note this makes it a reheated food, which may have implications for handing out doggy bags etc depending on catering regulations in your area.