Holding the chestnut by the thicker base, carefully make slight cuts in the tip of the chestnut skin to form a cross, trying not to cut into the chestnut itself (see picture above).

Place the chestnuts in a pan and cover with water to just a little over the level of the chestnuts. Warm over a medium-high heat to bring to a boil and boil for around 10 minutes. The ends of the chestnuts that you cut should fan open.

Remove the pan from the heat and take a few chestnuts out of the water at a time and carefully peel them with the help of a cloth, if it helps. It can be tricky as the chestnuts may be hot, but it is easiest when they are still warm and slightly moist (which is why just taking some out of the water at a time is suggested). Take care not to break them, if possible, and use the tip of a knife to get any bits of the skin that may be stuck in the crevasses. Discard the skins and cooking water.

Place the sugar and water in a clean pan and warm them over a medium heat to dissolve the sugar. Bring to a simmer and cook for a minute or two, then add the peeled, cooked chestnuts. Simmer them for around 10 minutes then remove the pan from the heat. If you like, you can transfer everything to a sealable container, or you can just set the pan aside, covered. Either way, let the chestnuts sit in the syrup at room temperature overnight.

The next day (around 24hrs later), remove the chestnuts from the syrup with a slotted spoon and set aside temporarily. Bring the syrup to a simmer again and add back the chestnuts. Simmer for 2-3 minutes then remove from heat and allow to cool again, then leave overnight.

Repeat this process two more times, ie bringing to a simmer 4 times in total, over 4 days. On the fourth day, after you have simmered and removed from the heat, take the chestnuts out of the syrup and set them on a parchment-lined baking sheet.

Preheat the oven to 250F/120C and place the chestnuts in the oven for around 1 hour until they are relatively dry to look at and touch. Allow to cool then either serve or wrap - they can be kept at room temperature but are best separated with parchment or in individual paper liners within a sealed container.