Peel and devein the prawns. Remove the head, and rinse thoroughly. Keep the tail on. Finely chop the tomato, and julienne the ginger. Thinly slice the chilies. I used some fresh purple chili peppers from the kitchen garden, which were not hot. You can use any chilies, but keep in mind that we don’t want to make the sauce hot. Just a subtle hint to cut through the creamy sauce is sufficient.