Blend desiccated coconut and hot water together in an electric blender or leave the coconut to soak in hot water for 20 minutes. Either way, pass the liquid through a strainer, squeeze out the coconut and retain the white coconut milk.
Grind coarsely chopped onions, garlic and ginger . Add coriander, cumin, salt, chilli powder and a little oil. Blend into a smooth paste in a blender. Peel and clean the prawns. Wash and pat dry. Chop all the vegetables. Shred the cabbage. Grate the lemon peel.
Heat oil in a large saucepan. Add grounded ingredients and fry for 3 minutes, stirring continuously. Add coconut milk and bring it to a boil. Add the mixed vegetables and cabbage together with the bay leaf and grated lemon peel. Continue to cook gently for 20 minutes, then add the prawns and cook for a further 5 minutes. Serve hot.