Prepare crab, if necessary. Heat oil and butter in a saucepan over moderate heat and saute the onion. Add the tomatoes, thyme, parsley, curry paste or powder and okra and cook for 5 minutes, stirring constantly. Add the whole hot pepper, fish stock, coconut milk, allspice, salt and black pepper. Stir in the crab meat, reduce the heat and allow to simmer for 10–15 minutes.