Cut the onion and the clove of garlic into fine cubes and fry until translucent. Then add the drained crabs and crayfish meat to the pan. After a minute add the curry paste and stir well. After a few minutes, stir in the cream cheese and add the white sections of the spring onions, cut into thin rings, and the leek, which has also been treated. After another 1-2 minutes, add the previously peeled and finely chopped tomatoes and the thinly sliced peppers. Season to taste with the fish sauce, orange juice and a teaspoon of ketchup. Then serve the previously cooked pasta with the sauce. The remains of the leek can be used as decoration.