Heat oil in a large saucepan over medium-high heat. Cook onion, carrot, celery and garlic, stirring, for 5 minutes or until softened. Add mince. Cook, breaking up with a wooden spoon, for 6 to 8 minutes or until browned.
Add paste, tomatoes, oregano, nutmeg and 1/2 cup cold water. Bring to the boil. Reduceheat to low. Simmer, uncovered, for 20 to 30 minutes or until thick. Season with salt and pepper.
Meanwhile, cook pasta in a large saucepan of boiling, salted water, following packet directions, until tender. Drain.
Divide pasta among serving bowls. Spoon over sauce. Serve topped with cheese.