Wash the meat, dab dry and season all around with salt and pepper. Rub with tarragon mustard (see illustration) and place in a roaster. Sprinkle with breadcrumbs and press them lightly on.
Cook the roast in a preheated oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer) for approx. 3 hours. If necessary, cover with a lid or aluminium foil approx. 1 hour before the end of the cooking time.
Peel the carrots, leaving a little green on the side. Wash the carrots. Clean the mushrooms, wash them if necessary and halve them if necessary. Clean, wash and cut spring onions into pieces. Peel and roughly chop the garlic.
Season everything with salt and pepper and distribute around the roast about 45 minutes before the end of the frying time. After another 15 minutes pour on apple juice.
Let the roast rest for about 10 minutes, then cut open. Serve with vegetables and stock. Baguette tastes good with it.