Mix half the melted margarine with the parsley in a small bowl and set aside.
Brush the pepper pieces with some of the remaining margarine and arrange them on a baking tray.
Preheat the oven at 200°C, 400°F, Gas 6 and cook for 10 minutes.
Add the mushrooms and tomatoes and brush the remaining margarine and cook for a further 5 minutes.
Cook the pasta and drain.
Add the vegetables to the pasta and season to taste.
Serve While hot