Scalloped potatoes are a type of casserole combining thin slices of potatoes, cheese, milk or cream, and breadcrumbs, at least in American and Irish versions of the dish. The word scalloped has multiple meanings in cooking, but does not, as one would suspect, have anything to do with the shellfish. Possibly, the word derives from an Old English word, collop, which itself derives from the Old French word, escalope.
Collops did not mean scalloped potatoes, but sliced meats, perhaps prepared with cheese and cream. To confuse matters, some recipes for potatoes include the addition of ham or bacon. A Yorkshire recipe for collops did rely on the potato, but referred to frying thin slices.
The original recipes may have derived from England or the Americas. Since potatoes are native to America, it makes sense to attribute the dish to early settlers. The recipe may just as easily been developed in England or Ireland, however.
As prepared by most Americans, this dish is made up of thin potato slices, sometimes separated by sprinkles of cheese or melted butter. Once the layering process is finished, milk or cream is added and the entire dish may be topped with more cheese or breadcrumbs. Some cooks prefer to boil the potatoes for about five minutes before slicing them and adding them to the dish, while others slice the potatoes raw. The dish works well with standard potatoes, or what many cooks might call baking potatoes.
Scalloped potatoes are generally baked for about an hour in a 350°F (176°C) oven, although baking times vary with the size of the dish. Potatoes should be well cooked but not mushy. Care should be used if the dish is prepared in a glass dish and refrigerated, as moving cold glass into a hot oven can cause the dish to break.
Many people make scalloped potatoes for traditional holiday meals, such as at Thanksgiving or Christmas. They can be prepared in advance and then baked when necessary, which can lessen preparation time on the actual holiday.
There are many variations on this dish. Meats can be added to turn a side dish into a main course, while vegetables like tomatoes, mushrooms, or onions can spice it up. Which cheese is used often depends on the cook's taste: some prefer American cheese, but fancier recipes may use Swiss, pepper jack, or aged cheddar.
Vegans can still enjoy scalloped potatoes by omitting the dairy ingredients. Soy or rice milk can be used in place of cow's milk, and tofu cheese works as an alternative to cow or goat cheese. This version may be more appealing to dieters as well, as omitting high fat cheeses and creams cuts the calorie penalty of consuming this dish.
If a cook is short on time, there are boxed versions available. These tend not to be favored by gourmets, as the potatoes often have a preprocessed taste that some find unpalatable. Made from scratch, scalloped potatoes take about 15 to 30 minutes preparation and only an hour to cook, so they are not too time consuming to make, and they are difficult to ruin if the cook watches the clock carefully.