Add the finely chopped onion and garlic to the same pan, and fry on medium to high heat until transparent. Add the chopped tomatoes and a pinch of salt and cover for a couple of minutes. Remove cover and stir, mashing the tomatoes slightly in the process. Fry until the water dries off. Add the Italian seasoning, pepper and then the cream and milk. When it starts to simmer, add the prawns. Add the chopped coriander and continue to simmer until desired consistency is reached. Add salt to taste.