Wash the tindas and wipe them dry. Slice off both ends and scrape off thick skin. Slit each tinda into four without separating the pieces. Mix half teaspoon turmeric powder, one tablespoon coriander powder, one teaspoon red chilli powder and salt and stuff the slit tindas with this mixture. Heat oil in a pressure cooker. Add the cumin seeds and when they change colour, add the onion and ginger-garlic paste and sauté for two to three minutes on medium heat. 

Add the tomatoes and sauté till they become soft and pulpy. Add the remaining turmeric powder, remaining coriander powder and remaining red chilli powder and stir well to mix. If the mixture is too dry sprinkle a little water and sauté for a minute or two.  

Add the stuffed tindas and sauté for three to four minutes. Add one cup of water and let it come to a boil. Close the cooker with the lid and cook till the pressure is released twice (two whistles are given out).  Open the lid when the pressure has reduced. Garnish with fresh coriander and serve hot.