Curried Prawns and Pineapple

• 750 g/1½ lb live prawns
• 1 onion, finely chopped

Boil the live prawns in boiling salted water for 10 minutes. Drain, peel and remove the black cord. Heat 3 tablespoons of oil in a pan, add the onion, garlic and curry powder. Cook, stirring all the time, for 5 minutes or until the oil separates from the onion. Do not allow to brown. Add the tomatoe