Scrape karela, slit, smear salt and keep aside for half an hour.
Drop them in boiling water for 2 minutes and remove; squeeze gently to remove excess water and keep them aside.
Grind coconut, green chillies, cumin, garlic and coriander with a little salt into a coarse paste.
Stuff karelas with the prepared paste, secure them with a thread. Keep the remaining paste for spreading over the karela.
Arrange the karelas in a flat kadai in a single layer, sprinkle oil over them and also spread the remaining masala over them. Cover with lid and cook for 4 to 5 minutes, with a little water over the lid.
Remove lid, turn the karela and let it cook for 3 to 4 minutes.
Sprinkle a few drops of water if necessary during cooking.
Remove the lid, keep the kadai for 2 more minutes on the fire so that the karelas are browned and fried well. Remove the threads and serve with rice and sambar.