Bubble and squeak is a traditional British breakfast made from boiled potatoes and cabbage. In modern times it is a dish made with the shallow fired leftover vegetables from a roast dinner. The main ingredients are potato and cabbage but carrots, peas, brussels sprouts, or any other leftover vegetables may be added. The chopped vegetables (and cold chopped meat if used) are fried in a pan together with mashed potatoes or crushed roast potatoes until the mixture is well-cooked and brown on the sides. The dish is so named because the cabbage makes bubbling and squeaking sounds during the cooking process.^[It is often served with cold meat from the Sunday roast and pickles or brown sauce or as an accompaniment to a full English breakfast.

The meat was traditionally added to the bubble and squeak itself, although nowadays it is more commonly made without meat – from Wiki.

Update 26th December 2019. St Stephen Day (Boxing Day) I like to eat bubble and squeak and this is a must go to meal after a few days of feasting at Christmas time. When I last cook my brussels sprouts I make sure to make a bit more extras saving just for this