How to Cook Like Heston

Heston Blumenthal's dulce de leche-style caramel sauce from How to Cook Like Heston is flavoured with potato skin

Heston: "Milk jam, or dulce de leche as it’s more commonly known, is made by slowly heating milk and sugar until it forms a jam-like consistency and soft caramel flavour. It can be made without the potato skins but they add an interesting roast potato flavour."

• 940g demerara sugar
• 860ml whole milk
• Skins from 4 baked potatoes

1. Put all the ingredients into a wide-bottomed pan and place over a medium-low heat.

2. Cook for approximately 2 hours, stirring regularly until a rich brown colour and a thick, spread-like consistency are achieved (the time will depend on the width of the pan). It is important to remove the foam that collects on the surface of the liquid throughout the cooking time as this can affect the texture of the final jam.

3. Strain and reserve in a container in the fridge covered with cling film touching the surface.