Wash the meat, pat dry and season with salt and pepper. Place on a drip pan and fry in a preheated oven at 175 degrees for 2.5 - 3 hours. Take out of the oven and let rest for 30 minutes.
Heat the fat. Fry the mushrooms. Season with salt and pepper. Thinly cut the camembert bark.
Bring 1/4 liter of water to the boil. Add the camembertree rind and the processed cheese and allow to melt while stirring. Pour in the cream and stir. Bring to the boil again. Season with salt and pepper. Take it off the stove.
Slice the roast and place in a large, flat roasting pan in a fan shape. Spread the mushrooms and the thinly sliced camembert on top and cover everything evenly with the cheese sauce. Cover and leave to stand overnight.
The next day, bake the roast for about 40 minutes at 175 degrees Celsius.