Reduce vinegar and 1 tablespoon of sugar by half. Mix with 3 tablespoons of olive oil. Clean, wash and chop the arugula a little smaller. Wash the fillet slices, dab dry and tap flat.
Season with salt, pepper and 1 pinch of sugar each. Clean the oyster mushrooms. Heat 2 tablespoons of oil in a large pan. Fry the oyster mushrooms in it, season with salt and pepper. Fry the fillet slices in 1 tablespoon of hot oil on each side over high heat.
Arrange rocket, oyster mushrooms and fillet slices in portions. Drizzle marinade over them. Sprinkle with parmesan. Serve garnished with thyme blossom.