Peel the potatoes and boil them in salted water until ready. Mash them, while also adding the butter and milk to them. Add the 2 beaten eggs. Grate the cheese, crumble the feta. Add them to the potato mixture.
Bake in the oven on baking paper for about 10 min., flip them over with a spatula and bake finished for another 10 min.
Serve with a dairy sauce or seasonal garnish.