Rub the chicken with turmeric and salt. Let stand for 15 minutes. Heat the oil over moderate heat and add sugar. Stir to melt. Add pepper and chicken. Brown on all sides 10 minutes. Remove chicken and set aside. Mix the spices together. Roast them in a dry skillet for 2 minutes. Stirring continously. Grind spices into powder. Mix with water and set aside. To make the gravy. Put the onions, garlic, ginger and paprika into food processor. Chop fine. Heat the oil in a pan over moderate heat. Fry the onion mixture, adding turmeric until light brown. Add spice water and mix. Cook 2 minutes to release aroma. Add yogurt, cook and stir 2 minutes. Add chicken, cover pan and cook over moderate heat for 30 minutes. Serve warm with rice.