Place the Rösti on a baking tray. Bake in a preheated oven (electric: 200 °C/ gas: level 3) for 15 minutes. Cut meat into strips. Peel and finely chop the onion. Clean, wash and slice the mushrooms.
Peel and thinly slice carrots. Heat oil in a pan. Brown the meat in it in portions. Add meat, onions, carrots and mushrooms to the pan and fry briefly again. Season with salt and pepper. Add cream and wine, bring to the boil and cook over medium heat for 5 minutes. Stir in sauce thickener, bring to the boil again and season with salt, pepper and lemon juice. Arrange the shredded meat with the rösti corners on plates. Garnish with a slice of lemon and parsley.
Season with salt and pepper. Add cream and wine, bring to the boil and cook over medium heat for 5 minutes. Stir in sauce thickener, bring to the boil again and season with salt, pepper and lemon juice. Arrange the shredded meat with the rösti corners on plates. Garnish with a slice of lemon and parsley. Serve with green salad with tomato marinade