Heat the oil in a large frying pan or saucepan and fry the onions for 3 - 4 minutes until golden. Add the garlic, fry for about 1 minute, and then stir in the tomatoes.

Blend the tomato puree with the stock or water and stir into the pan with the cumin, cinnamon and seasoning. Simmer, covered, over a low heat for 15 minutes, stirring occasionally. Do not allow to boil.

Add the prawns and lemon juice and simmer the sauce for a further 10 - 15 minutes over a low to moderate heat until the prawns are cooked and the stock is reduced by about half.

Serve with plain rice or in a decorative ring of Persian Rice, garnished with parsley.