Heat oil in large pan; cook onion, garlic, bacon and carrot, stirring, til carrot is just tender - about 8 minutes *.
Add mince and cook, stirring, til mince changes colour; then add undiluted soup, tomato paste, sauce and oregano and simmer, covered, about 15 mins or til mixture has thickened slightly.
While beef mixture is simmering, cook pasta and drain. Stir pasta into beef mixture, then spoon into an oiled deep 8 cup capacity ovenproof dish and sprinkle with cheese. Bake, uncovered, for 15 mins or until browned slightly.
*If you want to, you can add a stick of chopped celery along with the onion etc or add some mushrooms just before the mince.