1. In the food processor combine onion, ginger, garlic and green chilies.
2. Process until pureed well.
3. In a pan pour oil and sauté the onion mixture for 4-5 minute or until brown.
4. Add coriander, turmeric,, and red chili powder, continue stirring for 2-3 minutes.
5. Add tomatoes, sauté for another 3 minutes.
6. Add chicken pieces and mix well with the masala, add salt, potatoes and garam masala.
7. Add water to just cover the chicken. Simmer for 25 minutes covered or until chicken is done.
8. Garnish with chopped cilantro or curry leaves.