Wash the karela, then peel them lightly—just enough to remove the tough outer bumps.
Slit each karela lengthwise and scoop out the seeds, reserving any tender seeds for the stuffing.
Rub salt over the karela, including inside each slit.
Set aside for 15–20 minutes, then squeeze gently to remove some of the bitterness.
Rinse well to remove the excess salt, then squeeze out as much water as possible.
The rinsed and squeezed karela are now ready to be filled.
In a bowl, combine the chopped onions, green mango, karela peels, and reserved tender seeds.
Add the chopped green chilies.
Add the kalonji, crushed anardana, red chili powder, turmeric, crushed fennel seeds, coriander powder, garam masala, amchur powder, and salt to taste.
Add the jaggery powder.
Mix thoroughly until all the ingredients are evenly combined, then taste the stuffing and adjust the seasoning as needed.
Fill each karela firmly with the stuffing.
If needed, tie each stuffed karela with kitchen thread to keep it closed.
Once all the karela are filled, arrange them on a plate and set them aside until youare ready to cook.
Heat the mustard oil in a wide pan over medium-low heat.
Gently arrange the stuffed karela in the pan.
Cover and cook over low heat for 35–45 minutes, turning the karela occasionally for even cooking.
Allow them to brown slowly so the stuffing settles and the bitterness mellows.
When the karela are almost done, add any leftover stuffing to the pan and cook everything together for a few more minutes.
Once the karela are tender and lightly crisp, turn off the heat and let them rest briefly.
Serve the bharwan karela with hot rotis, parathas, dal-chawal, or dahi. The flavors deepen overnight, so the dish tastes even better the next day.