1.Short for bubble and squeak. Bubble is made from leftover boiled potato and greens, typically cabbage, fried together. Often offered as part of a British "fry up" or breakfast.
Hence 2. British rhyming slang
Bubble = Greek. Often used in a derogatory way
So this bubble come in the caff an' arsts for breakfast, no beans, no bubble. Farking cahnt!