Fry the beef in half the extra virgin olive oil for 5 minutes, until browned. Set aside. Fry the onion, celery, carrots, garlic and thyme in the remaining oil, until just softened, then return the beef and add the diced tomatoes, tomato paste and stock. Turn the heat to low and cook for 2 hours, adding water as necessary. Season with salt and pepper.
Cook the pasta in a large saucepan of rapidly boiling salted water according to manufacturer’s instructions until al dente, then drain well and toss with the pasta, parsley and cheese.