Scrap the outer skin of the karela (Do not peel). Then cut it into half vertically and thinly slice them. If the seeds are tough and mature then discard otherwise keep them as it is.
Take slice karela in a bowl and sprinkle salt over it.
Keep it aside for at least 20-30 minutes.
Meantime chop onion, green chili and prep rest ingredients.
After the resting time, squeeze out all the water.
Then rinse them under the water.
Making Sabji:
Heat the oil in a pan on medium heat. Once hot add cumin seeds and fennel seeds. Let them sizzle a bit.
Then add turmeric powder and hing, immediately add sliced onions, chopped green chili and ginger.
Sprinkle little salt, mix and cook till onions starts to soften.
Now add sliced bitter gourd, red chili powder and coriander powder, mix well.
Cover the pan with thali/plate which has rim around the edges. Add water on the plate and let the sabji steam cook on medium heat.
Do stir once or twice in between and cook till karela becomes soft and tender.
Lastly add sugar, amchur powder and garam masala, mix well.