Early casserole recipes consisted of rice that was pounded, pressed, and filled with a savoury mixture of meats such as chicken or sweetbread.

[2] Cooking in earthenware containers has always been common in most cultures, but the idea of casserole cooking as a one-dish meal became popular in the United States in the twentieth century, especially in the 1950s when new forms of lightweight metal and glass cookware appeared on the market.

[3] In the United States, a casserole or hot dish is typically a baked food with three main components: pieces of meat (such as chicken or ground meat) or fish (such as tuna) or other protein (such as beans or tofu), various chopped or canned vegetables (such as green beans or peas), and a starchy binder (such as flour, potato, rice or pasta); sometimes, there is also a crunchy or cheesy topping.

Examples include Lancashire hotpot (English), cassoulet (French), moussaka (Greek), and timballo (Italian).

[citation needed] In English-speaking Commonwealth countries like the United Kingdom, Australia, and New Zealand, the term casserole is most commonly used to refer to a dish of meat with vegetables (especially root vegetables) and a gravy-style sauce; dishes containing a large proportion of starchy ingredients, e.g., pasta or those cooked in creamy sauces are not generally referred to as casseroles, and might be called ‘bakes’ or ‘gratins.’ In the UK, the terms casserole and stew tend to be used interchangeably, although some distinguish them by saying stews are cooked on a stovetop while casseroles are cooked in an oven.