1. Fry and grind the pepper, mustard, fenugreek, coriander and turmeric and set aside.
2. Grind the red chilies to a paste.
3. Heat enough oil in a pan and fry a few curry leaves and tamarind, add finely chopped onions, crushed garlic and ginger, the red chili paste and the green chilies cut into small pieces.
4. Place the prawns in this, then add the ground spices and salt to taste, and enough water to cover the prawns.
5. Cook until water is absorbed and the prawns are tender.