Mix all the ingredients for the marinade to get a medium thick paste. Salt the steaks well, you can even tenderize them beforehand. Coat them on all sides with the marinade and leave them in a covered container in the refrigerator for several hours.
Clean the mushrooms and sauté them briefly in a little preheated oil. Arrange the steaks in a large greased tray and add the mushrooms on top. Clean and rinse the potatoes well. Cut them into pieces, but not all the way, to keep them whole. Sprinkle each potato well with salt, black pepper. Arrange them in the tray as well.
Pour a trickle of oil over them. On one side of the tray, fill up with the beer and gently shake. Add foil and put everything to bake in a heated to about 410°F (210 °C) oven. You can bake it without the foil near the end.