Clean the king prawns. Set aside.

Mix together ground turmeric, ground black pepper, Kashmiri chili powder, vinegar, salt, and a little water to make a smooth paste.

Now use the paste to marinate prawns. Place it in the refrigerator for 30 mins.

Heat coconut oil in a pan, and shallow fry the prawns (One minute on each side should be more than enough). Once fried, remove the prawns from pan, and set aside.

In the same pan, splutter mustard seeds, fenugreek seeds and curry leaves (Add more oil if needed). Fry sliced onions until brown. Then add ginger and garlic paste, and fry for a few seconds. Throw in the rest of the spices (chili powder, ground coriander and garam masala), and fry again. At this stage, you can add a little water. Finally, add the fried prawns and enough salt. Add enough water to cook the prawns, and make sure the roast doesn't stick to the bottom of the pan. Cook prawns until done.Garnish with more curry leaves if desired.