What is British bubble and squeak?

British bubble and squeak is a traditional, hearty, and economical dish made from leftover vegetables, typically potatoes and cabbage, fried together until crisp. It originated as a way to use up leftovers from a Sunday roast, especially on Monday. The classic recipe mixes leftover mashed potatoes or roasted potatoes with leftover cabbage, Brussels sprouts, carrots, peas, and sometimes leftover meat, then forms into patties or a large cake and fries in butter, lard, or oil until golden brown and crispy on outside and soft inside. The name bubble and squeak comes from the bubbling and squeaking sounds the vegetables make while frying in the pan. It is a staple of British home cooking, pub food, and is often served as part of a full English breakfast alongside bacon, eggs, and sausages, or as a side dish for roast dinners. Variations include adding cheese, onions, or leftover ham. Similar to Irish colcannon, but bubble and squeak is specifically fried, while colcannon is mashed. It is comfort food that is crispy, savory, and a clever way to avoid food waste, beloved for its simplicity and flavor.