Wash the brain thoroughly and boil in water. After boiling remove the brain from the water and remove any membrane and nerves carefully. Cut brain into small pieces.
Heat cooking oil in a pot or karai and fry the sliced onion until they are golden brown. Remove half of the onions and set aside. To the onion in the pan, add the spices, ginger paste, garlic paste, plain yogurt , green chillies and salt. Fry well for about 10 minutes by adding a little water if needed.
Add the brain and holding the pan by the handles, gently shake the pan to mix. Do not stir with a spoon. When the oil separates, sprinkle with chopped coriander, lemon juice, finely chopped ginger and the remaining brown onion.