Arrange your steaks in an oven dish or suitable baking container. Cut the onions and potatoes into circles, arrange them on top of the steaks.
Top with mayonnaise and add the spices. Bake in a preheated 356°F (180 °C) oven for about 1 hour.
Turn off the oven, grate the cheese into the dish and put it back in the oven to melt.