For the purée:
- 1/4 l whipping cream
- 200 g celearic (celery root)
- Salt, pepper
Sear the wild mushrooms in olive oil, season with salt and pepper. Let them cool and chop them finely. Add coarsely-chopped flat-leat parsley and thyme leaves. Mix with the breadcrumbs and eggs.
Lightly flatten the venison slices (pound gently with a meat tenderizer). Season with salt and pepper, then spread the mustard on each slice. Add the mushroom filling and roll the slices into roulades. Seal them with toothpicks. Season the outside with salt and pepper and brown on all slides in olive oil. Afterwards, roast them for ca. 4 minutes at 180 °C in the oven. Roulades should be medium (let them rest while keeping them warm).
Cook the celeriac (celery root) cubes in the cream until soft. Puree them in a food proessor and season with salt and pepper. For the shallot butter, cut the shallots into fine cubes and reduce them in red wine until almost all of the liquid is evaporated.
Remove the shallot-red wine mixture from the stove and add the cold butter. Season with salt and pepper. Add the lingonberries. Keep warm, but do not return to heat.
Place the purée in the center of the plate and arrange the lingonberry butter in a ring outside. Cut a roulade in diagonally in half and place on the purée. Garnish with chervil.