Heat the oven to 200℃.

Peel the potatoes and cut into thick cut chips. Finger width is ideal.

Par boil the potatoes in heavily seasoned boiling water for approx. 10 minutes, until you can easily poke a knife through the potato, but not enough that they break up.

Drain the chips into a colander and leave to steam dry.

Once they have dried, toss them with the flour until they are all coated.

Put the duck fat or sunflower oil into the largest baking tray you have and place it in the oven for about 5 minutes.

Take it out, then carefully tip the chips into the hot fat. It should sizzle. Move the chips apart so that they are not touching each other.

Bake in the oven for 50 minutes or until golden brown, occasionally turning them over.

Toss with sea salt and serve.