Put the sliced potatoes in a tray. Sprinkle with all of the spices + the oil and stir.
Pour water to submerge the potatoes halfway. Bake at 356°F (180 °C) until ready.
In the meantime, put the milk and feta cheese in a pot on the stove. Stir until the feta cheese melts.
Pour this mixture over the baked potatoes. Bake another 10 min. at 392°F (200 °C).