• 80 g (2¾ oz) butter
• 1 teaspoon finely chopped rosemary
• 1 teaspoon finely chopped sage, plus 8 whole leaves, extra
• 1 garlic clove, finely chopped
• 1 teaspoon sea salt
• ¼ teaspoon ground white pepper
• 1.2 kg (2 lb 12 oz) waxy potatoes, such as dutch creams, or all-purpose potatoes, such as desiree

Preheat the oven to 180°C (350°F). Put the butter in a small saucepan over low heat and add the chopped rosemary, sage, garlic, sea salt and white pepper. When the butter has melted, remove from the heat.

Line an ovenproof frying pan or a 20 cm (8 inch) pie tin with baking paper. Brush with some of the flavoured butter and then arrange the whole sage leaves in a decorative flower pattern on the base of the pan.

Peel the potatoes and slice them very thinly. A mandolin is perfect for this task, but if you don’t have one use a very sharp knife. Place a layer of potato slices in the pan, starting in the centre and fanning the pieces out over the base to form a petal pattern. Brush with some of the butter and then cover with another layer of potato slices. Repeat the process until all the potatoes have been used. Brush the remaining butter over the last layer of potato.

Bake for 1 hour, or until the potatoes are crispy and golden. Turn out onto a warm plate and serve in thick wedges.