In a large heavy based sauce pan that is very hot add the olive oil and then the beef rump and seasoned, cook until the beef has a little colour on it, then add the rosemary. Cook for a few minutes more until the rosemary becomes fragrant
Remove the beef and set aside then add the celery, onions and garlic. Cook for 5 mins or until soft.
Return the beef to the pan add the Marsala and cook for a further 5 mins. Add the tomatoes and cook slowly on the stove with a piece of grease proof paper on top of the sauce to stop it from evaporating too quickly. Cook for 2 hours over a low heat
Season with salt and pepper and with a whisk, stir well breaking up the tender pieces of meat to create a fine meat sauce.
Cook the spaghetti until al dente then mix together with the ragu and a knob of butter for extra sweetness. Toss well and serve in a large bowl – finish with the parmesan cheese and a slug of extra virgin olive oil