Peel and finely chop the onion. Peel garlic and chop very finely. Clean, wash and halve porcini mushrooms. Clean the shiitake, cut off the stalks, clean and cut the cap crosswise.
Heat clarified butter in a frying pan, fry onion and garlic while turning, remove. Add the mushrooms to the frying fat and fry all around, turning. Add onions and garlic again, mix and deglaze with broth and cream.
Bring to the boil, stir in the sauce thickener, bring to the boil again. Season to taste with salt, pepper and sugar. Stir cranberries into the sauce, except for 1/2 tablespoon. Keep sauce warm. Wash meat and dab dry.
Heat the oil in a pan. Fry the meat in it vigorously from each side for about 3 minutes, season with salt and pepper. Place medallions in a greased casserole dish, pour mushroom sauce over them and sprinkle with cheese.
Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for about 15 minutes. Meanwhile wash parsley and cut into fine strips, except for 1 stalk. Remove the casserole from the oven and sprinkle with 1/2 tablespoon cranberries and parsley strips.
Garnish with parsley leaf.