Peel the potatoes, then cut them into evenly sized chunks. Place the potatoes in a large bowl of cold water and give them a good rinse. Drain and repeat until the water runs clear. This removes excess starch, helping them crisp up beautifully.

Fill a large pot with fresh water and add a generous amount of salt. Bring to a boil, then add the potatoes. Cook until they’re just shy of falling apart – you want them soft on the outside but still holding together, around 10–15 minutes.

Drain the potatoes well, then let them steam dry in the colander for a few minutes. This step helps achieve a crisp crust during roasting.

While the potatoes are drying, preheat your oven to 220°C (430°F). Add the vegetable oil or duck fat to a large roasting tray and place it in the oven to heat up until shimmering hot. Carefully add the potatoes to the hot oil in the tray, tossing them to coat in oil. Roast in the oven for 45–55 minutes, turning them halfway through, until golden and crispy.

In the last minute of roasting, melt the garlic butter and drizzle it over the potatoes in the tray. Give them a final toss to coat in that fragrant garlic goodness, then return to the oven for another minute.

Remove from the oven and season with a little extra salt if desired. Serve hot and crispy, with that garlicky, buttery aroma filling the room.