Clean, clean and halve the mushrooms. Peel, wash and chop the potatoes. Cook in boiling salted water for about 15 minutes. Meanwhile wash the fillet, dab dry and season with pepper. Place the bacon slices next to each other on the work surface, place the fillet on top and roll it up. Fasten with wooden skewers.
Heat the oil in a pan and fry the fillet until golden brown. Peel oranges so that the white skin is completely removed. Cut oranges into slices. Remove the fillet, cut into slices and fry in the frying fat for 3-4 minutes on each side, remove and keep warm. Warm up the milk. Drain and mash potatoes. Stir in fat and milk. Season with salt, pepper and nutmeg. Fry orange slices in the frying fat briefly, remove. Put mushrooms in the pan and fry them until golden brown, season with salt and pepper. Wash the thyme, dab dry, chop finely and stir into the mushrooms.
Drain and mash potatoes. Stir in fat and milk. Season with salt, pepper and nutmeg. Fry orange slices in the frying fat briefly, remove. Put mushrooms in the pan and fry them until golden brown, season with salt and pepper. Wash the thyme, dab dry, chop finely and stir into the mushrooms. Arrange slices of orange, fillet and mushrooms on plates. Garnish with thyme and add mashed potatoes