Wash and peel bitter melon, cut in half, remove flesh and seeds. Cut into thick slices.
In a bowl take sliced bitter melon and add 1 teaspoon salt and 2 tablespoon lemon juice. mix well and leave for at least 30 minutes.
In a vessel take oil, heat on low flame and add garlic and fry till light golden.
Add dry whole spices (cumin, fenugreek, mustard) first, then powder spices (turmeric and coriander powder) Saute for 1 minute.
Add chopped onion, saute till onions are translucent.
Add chopped tomatoes, green chilli and ginger cover and cook for 5 minutes on low flame or till tomato are soft.
While gravy cooks, wash bitter melon slices in water and squeeze them to reduce bitterness.
Add sliced bitter melon, tamarind and brown sugar in gravy and cook for 10 minutes until soft.
Add 2 tablesppon oil and saute on high heat for a minute or more. Serve hot.