Scrape, wash and make a slit on one side of the bittergourds and deseed. Rub salt over and inside and leave aside for an hour. Wash under running water. Keep aside. Peel, wash and finely chop two onions.
Peel, wash and grind ginger and garlic to a fine paste. Clean, wash and chop coriander leaves. To prepare the stuffing, dry roast gram flour in a nonstick pan and sauté on low heat till it emits a nice aroma.
Remove from heat, transfer into a plate and allow to cool. Add one chopped onion, fresh coriander leaves, salt, red chilli powder, garam masala powder and carom seeds and mix well.
Stuff this masala mixture into each bittergourd and keep aside. Heat oil in pan, add the remaining chopped onion and sauté till light golden brown. Add ginger-garlic paste and sauté for two minutes.
Add coriander powder, red chilli powder, cumin powder, turmeric powder and mix well. Sauté the masala till it emits a nice aroma. Add the stuffed bittergourds, half a cup of water and salt.
Cover and cook on high heat for three to four minutes. Reduce heat and cook for ten to twelve minutes, stirring gently at regular intervals. Add tamarind juice and mix well.
Cover once again and let it cook for another ten to fifteen minutes till the bittergourds are properly cooked. Serve hot.