A whole potato baked in its skin until the interior is soft and fluffy and the outer skin turns crisp. The skin acts as a natural jacket, protecting the flesh during the long, hot bake and adding fibre, flavour, and nutrients concentrated just beneath it. Jacket potatoes are a staple of British and Irish cooking, served split open with fillings such as butter, cheese, baked beans, tuna mayonnaise, or chilli. Nutritionally they provide complex carbohydrates, vitamin C, potassium, and fibre, especially when the skin is eaten. Baking at around 200 degrees Celsius for an hour or more gives the best texture; microwaving is faster but produces a softer skin.