Parboil the potatoes

• Peel the potatoes and cut them into even chunks.
• Place them in a pot of salted water and bring to a boil.
• Drain in a colander once just tender at the edges.

Rough up the edges

• Shake the drained potatoes in the colander to roughen the surfaces.
• This creates the craggy texture that turns crispy.

Heat the oil

• Pour the olive oil into a baking tray and heat it in the oven until shimmering hot.

Roast until golden

• Tip the potatoes into the hot oil and turn to coat.
• Season with salt and black pepper.
• Roast, turning once, until deeply golden and crisp with fluffy insides.