Dab meat dry and season on both sides with salt and pepper. Spread 1 teaspoon of mustard on each roulade. Cover each with 2 slices of bacon and 2 plums. Roll up the roulades firmly and pin each one with a roulade needle.
Onions peel and roughly chop. Heat the oil in a flat frying pan. Fry the roulades in it for about 10 minutes. Preheat the oven (electric cooker: 200°C/circulating air: 175°C/gas: level 3).
Add the onions to the roulades and fry briefly. Deglaze everything with port wine and 400 ml water and bring to the boil. Stir in stock and season with salt and pepper. Braise open in the hot oven for about 1 1/2 hours.
Turn roulades in between. Cover the mould with aluminium foil approx. 20 minutes before the end of the braising time.
In the meantime peel, wash and slice the carrots. Clean the leek, wash thoroughly and cut into rings. Roast anise in a pot without fat while stirring and remove.
Melt the butter in the pot and steam the vegetables for about 10 minutes at medium heat. Pour on some water if necessary. Arrange roulades and vegetables. Sprinkle with aniseed.