Place onion, garlic, ginger, coriander, yoghurt and all the spices together until smooth. Place boned chicken thighs in a dish. Pour over the marinade, turn the chicken over to make sure that it is coated all over, cover and leave in the fridge overnight, if possible.
Heat the oil in a skillet or frying pan, take meat from marinade (reserve marinade) and seal both sides.
Add all the marinade, and simmer slowly for about 20-25 minutes, turning occasionally - to begin with the marinade looks watery and not that great! After a while it slowly thickens (as the meat cooks) into thick gravy that is spooned over the top of the chicken when served.
Serve with salads, spiced rice or my Gujarati Potatoes.Recipe #176179.
N.B If less heat is required, cut down on the chili powder to 1/4 teaspoon.