There's one question we get more than any other: how do you get roast potatoes properly crispy in an air fryer without them turning out dry or chalky in the middle? The trick isn't the air fryer at all — it's what you do before the potatoes ever go in the basket. We've made this method through six full Sunday roasts to make sure it holds up under real dinner-table pressure, not just as an isolated test batch.
Choosing and Cutting
Maris Piper and King Edward are the classic roasting varieties for a reason — their floury texture fluffs up at the edges when shaken, giving the surface area that turns crispy. Cut potatoes into even, fist-sized-halved chunks; wildly different sizes in the same batch means some will be done before others.
Why Par-Boiling Matters
Par-boiling roughs up the outside of the potato, giving the air fryer's hot circulating air something to grip and crisp. Skip this step and you'll get potatoes that are golden on the outside but soft rather than fluffy inside — this is the single most common reason readers tell us their air fryer roast potatoes 'don't turn out like the oven version'.
The Method
Par-boil the chunked potatoes for 8 minutes, drain thoroughly, and shake them roughly in the colander — you want the edges to rough up and fluff, not stay smooth. Toss in a tablespoon of oil (goose fat if you're going full traditional), then air fry at 200°C for 20–25 minutes, shaking the basket halfway through. Resist opening the basket in the first 10 minutes; that's when the surface is setting.
Fitting It Into a Full Roast Dinner
A single-basket 4–5L model comfortably fits a full batch for four people on its own. For a Sunday roast alongside other trays, a dual-zone model like the Ninja Dual lets you run potatoes in one basket while a chicken breast, gammon joint or a second veg tray finishes in the other — using the Match Cook setting so both zones finish together rather than one going cold while you wait on the other.
Common Mistakes
Overcrowding is the biggest one: potatoes need space between them to crisp on all sides, so a large batch is better done in two rounds than crammed into one. The second is under-seasoning before cooking rather than after — salt added before the fry helps draw moisture to the surface, which is part of what crisps up.