Prepare the filling: in a bowl, mix ¾ of the grated cheese with milk and egg, salt and spices. Put the mixture in the refrigerator.
Rub a baking dish with garlic and lay out the potatoes, overlapping them.
Pour the dressing over the potatoes, spread the remaining cheese evenly. Bake the potatoes in the oven for 30-40 minutes at 180°C.