Boil 2-3 cups of water in a saucepan, add turmeric powder. On boiling add brains and boil for few minutes. Take out brains and de-vein them with hand gently.
In a pan, heat oil and add onions and fry them until brown and add tomatoes and fry until they are soft. Add spices and mix well. You can add 1-2 teaspoon of water in between to avoid burning of spices. Add brain and fry them for 7-8 minutes until oil separates. Add chopped chilies, ginger and coriander for garnish.