What is the bubble in bubble and squeak?

What is the bubble in bubble and squeak? The origins of the name bubble and squeak are not known, but there is a reference in the “Classical Dictionary of the Vulgar Tongue” from 1785: “Bubble and squeak is beef and cabbage fried together. It is so-called from its bubbling up and squeaking while over the fire.”

The origins of the name bubble and squeak are not known, but there is a reference in the “Classical Dictionary of the Vulgar Tongue” from 1785: “Bubble and squeak is beef and cabbage fried together. It is so-called from its bubbling up and squeaking while over the fire.”