Rosemary roast potatoes

Before you start

Why they’re the best roast potatoes
A good wash: As you peel and chop your potatoes, putting them in a large bowl of water doesn’t just stop them discolouring – it helps wash off some of their starch. Starch is the enemy of crispiness, so by giving them a good swish around in the water, draining them, then cooking them in fresh water, you’ll get crisper roasties.

Softly simmered: Some roast potato recipes call for you to boil them until they’re almost falling apart – we find this provides rough edges, but a lot of your potatoes turn to mush and become waterlogged, which stops them crisping up. You just want to gently simmer them enough so their outsides are soft enough to rough up – the centres will steam into fluffy deliciousness in the oven.

Out to dry: Throw wet spuds into hot fat and you’ll not only be diving for cover as the oil splutters – you’ll have a harder time crisping up your potatoes. Leave them to steam-dry after simmering them (ideally on a wire rack) to ensure they’re as dry as possible before they hit the roasting tin.

Choose your fat: Our two favourite fats for roasties are goose fat or vegetable oil – both have a high smoke point which is key, as you want to get them as hot as possible before they touch the potatoes (cold oil will be absorbed by the spuds rather than crisping up the outside). Which one you choose is down to preference (or whether there are vegetarians at the table) – goose fat provides a richer, almost creamier spud, while vegetable oil offers maximum crispness.

Salt – then salt again: Potatoes can take (and need) a fair bit of salting, and using both fine and flaky ensures an even seasoning with little pops of crunch throughout. Whizzing some with rosemary gives you an instant flavour boost, while seasoning throughout the process – in the water, when they first go in the oven, at the end of roasting and then a final sprinkle before serving – builds layers of saltiness without becoming overpowering.

Make ahead: You can parboil and steam dry the potatoes, then keep them chilled in the fridge (covered) for up to 3 days before cooking.