Let me preface this by saying that thereās no such thing as ātoo manyĀ mashed potatoes,ā but I am definitely guilty of always making too many mashed potatoes. Dinner for me and my roommate? A five-pound bag should be enough. This means I am regularly tasked with figuring out what to do with the remaining four-ish pounds of mashed potatoes the next day (and the next dayā¦ and sometimes the day after that).Ā Shepherdās pie is always an option, and in regular rotation in our house. Sometimes Iāll just fire up the griddle and fry a patty of leftover mashed potatoes until crispy and deep golden brown on both sides to have with breakfast.
I thought Iād run out of things to do with leftover mashed potatoes until I stumbled across a recipe for the delightfully named rumbledethumps in Ben MervisāsĀ The British Cookbook. At first glance, the dish seems to be a cousin of colcannon, an Irish staple of mashed potatoes and cabbage, though this version is covered in cheddar cheese and baked in a casserole dish. In fact, Mervis calls rumbledethumps āScotlandās answer to the English bubble and squeak.ā The latter is leftover mashed potatoes and cabbage mixed together, sometimes with bacon or onions, and pan-fried until crispy.
As Mervis describes it, all three of these are related recipes that make the most of whatās around, which, in this case, is potatoes andĀ cabbage (and sometimes kale, according to Mervis). He tells me that bubble and squeak is typically served at breakfast, while colcannon is more of a lunch and dinner dish, and rumbledethumps can be made any time of day. And where do they get their names? Mervis tells me that rumbledethumps āis said to come from the process of mashing the potatoes (rumble) and popping them into the dish (thump). Fantastic, isnāt it?ā Meanwhile, ābubble and squeak gets its name from the sound it makes when it hits the pan of hot oil.ā Colcannon, which Mervis believes is likely the earliest invention of the three, is the only one without an onomatopoeic name. āThe ācolā in colcannon likely comes from the Irish cĆ”l,ā which means cabbage or kale.
Of the three, Mervis describes rumbledethumps as the most āglammed up,ā served in a baking dish and covered in gooey shredded cheese. Itās beautifully simple to make, consisting of just a few ingredients, and it tastes rich and homey. Mervis calls it a sort ofĀ breakfast casserole, and I have to say that the dish goes very well with some thick, crispy bacon and a couple of fried eggsāall the essentials for a hangover cure or a hearty Christmas breakfast.
If youāre making rumbledethumps without the help of leftover mashed potatoes, start by boiling potatoes until fork-tender, boiling sliced cabbage until soft. Then you just mash these two components together with lots of butter, scoop it all into a baking dish, cover with cheese, and bake. The end result is fluffy mashed potatoes, properly enriched with buttery flavor, bits of tender cabbage throughout, and gooey, salty, nutty cheddar bringing it all together.
If you find yourself swimming in mashed potatoes after your next big holiday meal, rumbledethumps are yourĀ brunch move. If youāve already got leftover mashed potatoes and cabbage, most of the work is already done, giving you time to sleep in before firing the oven back up for your hungry guests.
