Soak rolls in cold water. Knead minced meat, egg, squeezed out roll and mustard. Season with salt and pepper. Form into a loaf and roll in the fried onions. Place on a baking tray covered with oil.
Grate the cheese and sprinkle over it. Bake in the preheated oven (electric cooker: 175 °C/ gas: level 2) for approx. 1 hour. In the meantime clean, peel and slice the carrots. Clean, wash and slice the leek.
Cook the carrots in 400 ml boiling salted water for about 15 minutes. Add leek after about 5 minutes and cook. Refine with cream. Add sauce thickener, bring to the boil again briefly. Season to taste with salt, pepper and nutmeg.
Cut the roast open and arrange with the vegetables. Serve garnished with parsley as desired. Boiled potatoes taste good with it.