Preheat oven (electric cooker: 150 °C/circulating air: 125 °C/gas: see manufacturer). Brown the steaks in 2 tablespoons of hot oil for approx. 2 minutes. Season with salt and pepper and place on a tray. Fry in a hot oven for about 15 minutes.
Mix vinegar, salt, pepper and 3 tablespoons of oil. Peel onion and cut into strips. Slice beetroot into thin slices. Mix everything. Mix crème fraîche and horseradish, season. Wash and chop the parsley.
Arrange everything and sprinkle with parsley. Serve with baguette.