Irish stew is a traditional folk stew that first appeared at the beginning of the 19th century and was developed out of necessity to make a meal out of available, leftover ingredients. Originally, the stew was made only with mutton, onions, potatoes, and sometimes barley, while lamb meat and other root vegetables like carrots, turnips, and parsnips were added later. It is said that goat meat was also used in the past, but besides the previously mentioned mutton and lamb, beef is a common addition in today's recipes.
Given that the meat used in the dish is chewy and hard, usually bone-in, the stew is cooked slowly for a couple of hours so that the meat turns tender and releases the fat into the stew, thus enhancing the flavor of the entire dish. A stew made with Guinness stout has gained widespread popularity throughout Ireland as it intensifies the flavors and gives the broth a rich, brown color.