Clean or peel the vegetables, wash and cut them into very small cubes. Peel and finely dice the onion. Heat the oil in a large pan. Stir-fry the minced meat for 5-8 minutes until crumbly. Add vegetables and onion, dust with paprika and continue frying for 2-3 minutes.
Stir in the tomato paste, sweat briefly. Add tomatoes, juice and stock, bring to the boil and simmer for 15-20 minutes, stirring continuously. Season to taste with salt, pepper and sugar.
Meanwhile cook the pasta in 3-4 l boiling salted water (approx. 1 teaspoon salt per litre) according to the instructions on the packet. Whip cream until semi-stiff. Grate the Parmesan cheese or slice it into thin shavings (best with a peeler).
Drain the spaghetti. Arrange on four (preferably preheated) plates. Pour over the bolognese and place 1 blob of cream on each plate. Serve sprinkled with parmesan.