1. Heat oil, fry onion till it becomes transparent. 2. Put in tomatoes, thyme & parsley, ginger/garlic cook till a thick gravy is obtained. 3. Add the tomato purée if used and 2 pints of water and bring to the boil. 4. Put in crab, vestin, salt & pepper. 5. Reduce heat and allow to simmer, uncovered, for at least half an hour. 6. Serve hot.