Sauté the diced onions and garlic in a roasting pan or casserole and then sear the meat, add the tomato paste and season with salt and pepper. Then deglaze with the red wine and the stock. The meat should be covered in the liquid. Let it simmer for a good 3.5 hours.
The meat then has to disintegrate while stirring. Season again to taste.
Cook the fettuccine aldente and serve with the sauce.