In a saucepan, combine the soaked chana dal, 1 tablespoon ginger garlic paste, turmeric powder and red chili powder. Add water; the water should cover the lentils entirely. Bring to a boil then lower to a gentle simmer for about 35-40 minutes. Add salt half-way through the cooking process (it will bring out the natural flavor of the lentils and the lentils will be more tender) and keep stirring every now and then so the lentils don't stick to the bottom of the pot. The liquid should have evaporated. Remove any liquid (if any).
Take the bitter gourds and peel off the skin. Cut each bitter gourd longways and de-seed them. Sprinkle salt all over the bitter gourds to cover them well with salt. Set aside for at least 3 hours.
now wash bitter gourd.
heat the oil and fry bittergourds in oil on medium heat until they turn golden.Now add sliced onions,fry bitter gourd with oil,tomatoes and green chillies in dal.