How to turn leftover cooked potatoes into dinner

The Guardian

08-04-2025

How can I turn leftover cooked potatoes – mashed, roasted, boiled – into dinner?
This sounds like a job for queen of spuds Poppy O'Toole, whose latest book just so happens to be all about the tuber. We all know that mashed potatoes can cause heated debate, with smooth and buttery making some folk purr, while others prefer a bit of texture, and this also affects what you do with any spares. 'It can be difficult to use leftover mash, because many recipes depend on how creamy you like it to begin with,' says the author of The Potato Book, although she says one 'surefire way' begins by putting a good splash of olive oil in a frying pan on a medium-low heat. 'Fry two chopped spring onions [green bits and all] until soft, add the leftover mash, and fry until hot and almost caramelising.' Season, and you've got a great base for all sorts.
Alternatively, O'Toole might mix her mash with a handful of crumbled feta, some cooked and squeezed spinach, a pinch of chilli flakes, a little grated nutmeg and lemon zest, plus salt and pepper. 'Divide into pingpong ball-sized portions, then wrap in filo glued together with a touch of water. Shallow fry in oil until golden and crisp all over.' Perhaps the easiest solution of all, though, is to use excess mash to thicken soups: 'Sweat some leeks, add the mash, season and cover with vegetable stock and 100ml whipping cream,' says O'Toole, who then cooks the lot for 30 minutes before tucking in with a good hunk of bread.
The first job with leftover roasties, meanwhile, is to bring back their crispness. 'Chop them and pan-fry in a drizzle of oil until golden and sizzling,' O'Toole says, then serve with a fried egg and thick-cut ham. 'Or, if you're feeling fancy, toss them in a spiced tomato sauce for a speedy take on patatas bravas – simple but delicious.' Mind you, accessorising will always set you apart. 'You don't necessarily need to transform roast potatoes into something else,' says Stuart Andrew, head chef at 64 Goodge Street in London, 'but you could freshen them up with a little persillade [chopped parsley and garlic] or, for something rougher around the edges, whack mayo and chilli oil on top.'
Gratins are, of course, always a good idea, and they're an excellent home for leftover boiled potatoes. Take a leaf out of Andrew's book with a gratin Savoyard: 'Rub a baking dish liberally with unsalted butter and garlic, then layer up the sliced boiled potatoes with salt and pepper, some grated gruyere, sliced onion, parsley and mushrooms, much as you would a lasagne.' Pour over cream, dot with butter and bake until golden. 'Serve with a frisée salad dressed with a mustard vinaigrette, and it's actually quite a light meal.'
For O'Toole, however, excess boiled potatoes mean one thing: smashed spuds. 'Grab a jar [or anything with a bit of weight], press down on the spuds to break them up a bit, then brush with oil and coat in plenty of spices [smoked paprika, fennel seeds, ground allspice, say].' Roast, turning halfway, until golden and crisp. That said, the exception to O'Toole's rule is when she's in 'barbecue mode', when she'd chop boiled potatoes to mix with a mayo dressing for a classic potato salad. When said mode can next be activated, though, is anyone's guess.
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