Au gratin potatoes are a popular side dish often served alongside chicken, beef, or another main course. This dish consists of thin slices of potatoes layered with cheese, milk, and spices, then baked to a golden brown. Many believe that au gratin potatoes originated in France, and are based on a dish known as gratin Dauphinois after the Dauphine region of France. Au gratin potato recipes in United States (US) cookbooks date back to at least 1894, and many US recipes refer to this dish as scalloped potatoes.
The word gratin is passed on the French very gratter, which means to scrape. It refers to the flavor-rich scraps left over in the bottom of a pan after a baked dish has been consumed. Gratin dishes attempt to recreate these delicious scraps on the top of a baked dish using breadcrumbs, cheese, butter, or cream. This cooking technique can be applied to many different types of dishes, including potatoes.
Gratin dishes usually call for the use of a gratin pan, which is a shallow pan that can safely be used in the oven. These pans are often placed right on the table so that guests can serve themselves. Many gratin pans are fairly decorative, and made from ceramics and other fine materials to give them an attractive appearance.
Recipes and ingredients used for au gratin potatoes can vary widely by region and personal preference. All start with a base of thinly-sliced potaoes, which are layered in a baking dish. Grated or crumbled cheese is added to the mixture, along with milk, cream, or butter. Many chefs flavor au gratin potatoes with salt and pepper, while others add bacon for a rich, meaty taste. Traditional recipes often call for garlic and onions, and most versions of this dish feature a top layer made from cheese, eggs, and breadcrumbs.
Given the high concentration of butter, milk, cheese, and cream found in au gratin potatoes, it's no surprise that this dish is very high in fat and calories. Like other high-fat dishes, au gratin potatoes should be eaten in moderation as part of a balanced meal. To cut fat, some recipes call for skim milk or water in place of the traditional butter and cream. Others use garlic and herbs for flavor in order to cut out salt and butter. Many grocery stores sell a pre-manufactured version of this dish in a box or pouch, which often requires adding only water and milk, resulting in a lower-fat alternative to homemade au gratin potatoes.