Wash the meat and dab dry. Rub with salt and pepper. Peel the onions and cut them in half. Peel and halve 2 carrots. Place the meat, onion quarters and carrot halves on the fat pan of the oven and bake in the preheated oven (electric range: 175 °C/ gas: level 2) for approx. 1 3/4 hours.
Gradually extinguish with 3/4 litre of water. In the meantime finely dice the remaining onions. Clean, wash and slice the remaining carrots. Finely dice the bacon. Grind or finely crumble white bread in a universal chopper.
Mix 2 tablespoons mustard, egg, white bread and bacon. Sprinkle the crumbs on the roast about 20 minutes before the end of the frying time and press down carefully. Caramelise the sugar in a pan over medium heat, add 200 ml hot water and vinegar while stirring.
Stir in the remaining mustard. Bring to the boil and add carrot slices and remaining onions. Simmer for 8-12 minutes at low heat. Meanwhile wash parsley, dab dry and chop finely, except for a little bit for garnishing.
Take the roast out of the oven and let it rest for a while. Pour the roast stock through a sieve into a pot. Add cream and bring to the boil. Stir in the sauce thickener and bring to the boil again.
Season to taste with salt, pepper and sugar. Sprinkle vegetables with parsley and arrange roast on a plate. Serve garnished with the rest of the parsley if you like.