Blend spices, garlic, tomato sauce, water and yogurt in the food processor for 1 minute. Pulse a few times in between so the batter is not too runny, set aside.
Sauté onion in oil for 2-3 minutes until they begin to turn golden in color, add chicken pieces, continue cooking till onions are transparent and tender and chicken is reasonably well-cooked.
Pour spice/tomato mixture over the chicken and onions and bring to a boil, stirring well.Simmer, covered, stirring occasionally until chicken is tender for about 25 minutes.Serve hot,garnish with fresh coriander leaves.