Milk pie, or galatopita, is one of the most elegant, sumptuous, and seductive Greek recipes. It is a version of the sweet milk pie, which features three basic ingredients: phyllo pastry, milk, and rennet or feta cheese. People in Thrace used to make milk pies for Whit Monday or Pentecost Monday, also known as Monday of the Holy Spirit, that is, the holiday celebrated the day after Pentecost.