Boil up plenty of salted water. In the meantime peel and chop the onion.
Heat the oil in a large frying pan. Fry the mince in it until crumbly. Fry the onion and soup vegetables briefly. Season with salt, pepper and thyme. Add tomato paste and sweat it on. Pour on red wine and a good 1/4 l water, add stock and bay leaf.
Bring everything to the boil, cover and stew for about 10 minutes.
Cook the spaghetti in salted water for about 10 minutes until al dente. Dice the beetroot, add to the sauce and continue to braise for about 2 minutes. Season to taste with salt and pepper. Drain the spaghetti. Serve with the bolognese in deep plates.
Crumble cheese over it.