Rumbledethumps: The Borders Dish of Potato, Cabbage and Cheese

Rumbledethumps is mashed potato and swede folded through buttered cabbage, baked under a layer of cheese. It belongs to the Scottish Borders, it is built to use up what is already cooked, and the name — which sounds invented — is genuinely the traditional one, from Scots rumbled (mashed together) and thumped (bashed).

It is the best of the Scottish mashed-vegetable dishes because it is the only one that goes in the oven, and a browned cheese crust changes what a plate of mash can be.

What goes in it

Three vegetables and cheese:

• Floury potato — the bulk.
• Swede — neeps here, and the ingredient that separates rumbledethumps from its Irish and English cousins.
• Cabbage, savoy or plain green, shredded fine and wilted in butter.
• Mature cheddar on top. Scottish, ideally — Orkney or Isle of Mull both work hard here.

Butter throughout, salt, and more black pepper than feels reasonable. Chives are common and optional. Onion or leek, softened with the cabbage, is a legitimate addition and not universal.

The method that matters

The dish is simple, so the two technical points carry all the weight.

Drain everything properly, and cook the vegetables separately. Potato and swede take different times and hold different amounts of water. Boiled together, the potato overcooks while the swede is still firm, and you end up mashing water into the dish. Wet rumbledethumps will not brown — it steams under the cheese instead.

Wilt the cabbage; do not boil it. Five minutes in butter in a wide pan. Boiled cabbage adds water and loses its bite, and the contrast between soft mash and cabbage with some structure left in it is most of the pleasure.

Then fold rather than beat. Streaks of green through the mash are correct — this is not a purée.

The oven stage is not optional

Rumbledethumps that has been mashed and served straight from the pan is a nice bowl of mash. What makes it the dish is twenty-five minutes at a high heat under grated cheese, until the top is brown and the edges have caught. Rough the surface with a fork before the cheese goes on: the peaks catch and crisp, the troughs stay soft, and you get both textures in a forkful.

Variations that work, and one that doesn't

Kale instead of cabbage is common and good — it needs a minute or two longer in the butter and gives a firmer, more mineral result.

Onion or leek, softened alongside the cabbage, adds depth and is entirely traditional in some households.

Bacon or ham folded through turns it from a side into a supper. Not traditional; nobody will mind.

A layer of cheese through the middle as well as on top is worth doing if you are making it deep in a large dish, since otherwise the bottom third is unseasoned mash.

The one that does not work is swapping the swede for more potato. It is tempting — swede is a nuisance to peel and some people simply do not like it — but the swede is what makes this a Scottish dish rather than colcannon with cheese on it, and its slight bitterness is what stops the whole thing being bland under the cheddar. If you genuinely dislike swede, make colcannon and enjoy it.

Rumbledethumps, clapshot, colcannon and bubble and squeak

Four dishes of the same family, routinely confused:

The Scottish pair both contain swede, which the Irish and English versions do not. The split between the two Scottish dishes is cabbage and cheese: clapshot has neither.

It wants leftovers

This is a dish designed around Sunday. Leftover mashed potato and leftover mashed neeps — the latter being what a Burns supper or any roast leaves behind in quantity — plus half a cabbage, and you have rumbledethumps with fifteen minutes of work.

Made from leftovers it is also drier, which as above is exactly what you want for browning. Starting from scratch is perfectly fine; you just have to be more careful about draining.

What to serve it with

Traditionally alongside roast or boiled meat, or with sausages. It is substantial enough to be a supper on its own with a fried egg on top, and it reheats well — covered, in the oven, until the cheese re-crisps. Microwaving it works and forfeits the crust, which is the point of the dish.

Frequently asked questions

What is rumbledethumps?

A traditional dish from the Scottish Borders of mashed potato and swede folded through buttered cabbage, topped with grated cheese and baked until browned. The name comes from Scots words for mashed and bashed together.

What is the difference between rumbledethumps and clapshot?

Clapshot is potato and swede mashed together with butter, from Orkney, and contains no cabbage and no cheese. Rumbledethumps adds cabbage and is baked under a cheese crust. Both are Scottish and both use swede, which distinguishes them from Irish colcannon.

Is rumbledethumps the same as bubble and squeak?

No. Bubble and squeak is an English dish of leftover potato and greens fried in a pan. Rumbledethumps contains swede, is baked rather than fried, and is finished with cheese.

Can you make rumbledethumps ahead?

Yes — assemble it in the dish, cheese and all, and refrigerate for up to two days. Bake from cold, adding about ten minutes. It also freezes well before baking.

What cheese is best for rumbledethumps?

A mature cheddar with enough character to be tasted through the potato. Scottish cheddars from Orkney or the Isle of Mull are the natural choice; a strong farmhouse cheddar from anywhere does the job.