Directions: 1.Put the onion, garlic and oil into a medium saucepan and stir well. Heat until sizzling, then add 2 tablespoons of water, cover and saute very gently for 5 minutes until softened.
2. Add the vermouth or wine, if using, and cook until reduced by half, then stir in the chopped tomatoes, oregano and seasoning. Bring to boil, then simmer for 10 minutes.
3. Meanwhile, boil the spaghetti according to the pack instractions, then drain but leave slightly wet by tipping straight back into the pan.
4. Add the prawns and double cream to the pan, reheat, sprinkle with chives, and toss into the spaghetti. Serve at once.
Variation: if you add 200g clams in brine, it will give you a dish similar to the classic Italian Spaghetti alla Vongole.