- Roast the spices cumin,fennel, Fenugreek, corinader, pepper, Cinnamon,cloves,poppy seeds,mace, cardamom,red chilli and keep it aside to cool. Then grind it to a fine powder form. Chop the onion, tomato and green chilli finely. Heat oil in a pan. Put in mustard seeds and let it splutter. Then add in the hing and curry leaves. Next, add in the onions and green chilli. Fry till the onions are soft. Now add in the tomato, tamarind paste, ginger-garlic paste, chilli powder, coriander powder and turmeric. Cook till the tomatoes are soft. Put in the prawns, salt and grounded masala powder. Pour in about a cup of water. Simmer till the prawns are cooked and the gravy is a little thick. Serve it hot with rice.