What is "bubble and squeak"?

Bubble and squeak is a traditional British dish made from mashed potatoes and vegetables that are fried together until crisp. It is usually served as a side dish, but can also be served as a main dish. It is a popular dish in the United Kingdom and is enjoyed all over the world. Additionally, it can be served with a variety of sauces and accompaniments, such as ketchup, brown sauce, or Worcestershire sauce. It is often made with leftover vegetables from Sunday lunch, or with leftovers from Christmas dinner. It is also a popular British appetizer. Bubble and squeak is thought to date back to the early 1800s and is a great way of using up leftover mash, sprouts and cabbage.