Cook rigatoni pasta in a large pot of boiling salted water until al dente. Drain well. Set aside.
In a large frypan, fry mince until cooked through but not brown. Add chopped onions and minced garlic. Stir and cook until soft. Add sliced mushrooms and cook about 5 minutes. Add chopped green capsicum and cook slowly until soft. Drain off any excess fat.
Stir in tomatoes with juice, tomato paste, fresh basil and pepperoni. Bring to a boil. Reduce heat and add cooked rigatoni. Season with salt and pepper to taste.
Simmer 20 minutes, stirring occasionally, until most of the liquid has been cooked off.