Bring a large saucepan of lightly salted water to a boil. Cook pasta for 8 to 10 minutes or until al dente; drain.
In a large frypan brown beef over medium heat. Drain fat from frypan and transfer meat to a bowl.
In the same frypan cook onion and capsicum in butter until tender. Stir in tomatoes, mushrooms, olives and beef then season with oregano. Simmer for 10 minutes.
Preheat oven to 180 degrees C. Lightly grease a 20x30cm baking dish.
Arrange half of the cooked fettuccine in the prepared dish, top with half of the beef and vegetable mixture then sprinkle with 1/2 cup of Cheddar cheese and 1/2 cup of mozzarella cheese. Repeat layers. Mix together soup and beef stock until smooth then pour over casserole. Sprinkle with Parmesan cheese.
Bake in preheated oven for 30 to 35 minutes or until heated through.