Heat the oven to the max. Cut the pre-boiled potatoes into pieces and place them in a pre-greased baking dish.
In the heated oil, fry the finely chopped onions, add feta once removed from the stove and flavor with the spices. Pour this mixture over the potatoes, gently stirring.
Pour the milk, in which you've dissolved the cream, over the potatoes. Top with spices and grated cheese. Bake for 15 minutes to a nice tan.