Season the steaks and roll them in flour. Braise them on both sides. Braise the mushrooms in the same oil. Take them out and braise the onions, garlic and flour.
Pour in the milk and mash them. Return the mushrooms to the stove and take them off after 10 min. Arrange the steaks in the middle of an oven dish, while overlapping them a bit.
Peel the potatoes, cut them and arrange them around the steaks. Pour on the mushroom sauce and bake at 392°F (200 °C) for 40 min. or until ready. Sprinkle with chopped parsley.