Every recipe I see online for Bubble & Squeak uses mashed potatoes. But I don't think it's traditional to have mash with Christmas dinner in the UK, so do people make mash just to make Bubble with their leftovers? But surely some of the leftovers are your roast potatoes?
I'm not from the UK and my English DH's family always just chop the leftovers up, stick under the grill, and call it b&s. But I'm intrigued to make a "proper" one.