Potato, leek, and chicken pie is a traditional savory pie originating from Ireland. The pie crust is usually made from shortcrust pastry, phyllo pastry, or puff pastry. The pie is filled with a combination of potatoes, butter, chicken pieces, leeks, mushrooms, mustard, milk, flour, sage, salt, and pepper before it's baked in a preheated oven until golden brown and crisp.