Wash the meat, dab dry and season with salt and pepper. Peel and finely chop the onion. Heat 1 tablespoon of oil in a small pan, fry the onions until translucent, remove from the heat and add the herbs.
Clean and sanitize the mushrooms. Heat 1 tablespoon of oil in a frying pan, fry the meat thoroughly all around, add the mushrooms and fry briefly. Spread the onion and herb mixture over the roast. Roast in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 45 minutes.
In the meantime, peel the potatoes, wash them thoroughly and cook them in boiling salted water for about 20 minutes. Meanwhile wash parsley, shake dry and chop finely. Take the roaster out of the oven, lift out the meat and let it rest for 3-4 minutes.
Deglaze frying pan and mushrooms with cream, bring to the boil and season with salt and pepper. Drain the potatoes. Cut the meat open. Arrange meat and mushroom sauce on a plate. Garnish with parsley.
Add potatoes sprinkled with parsley.