Bring a large pot of lightly salted water to a boil. Add the fettuccini and cook until just tender. While this occurs, place Knorr Alfredo Pasta Sauce Mix, milk and butter in a small pot and prepare as per package directions. Heat the oil in a large skillet set over medium heat. Add the bell pepper and cook 1-2 minutes. Pour in the pasta sauce and add the prawns. Drain the fettuccini well, and then add to the skillet. Mix well, and then spoon pasta into bowls. Sprinkle with parsley and serve.