This started off as a bit of an experiment when I stayed over at Alice Temperley's house one weekend and her husband Lars had just finished squeezing grapefruits for breakfast. The skins almost went in the bin but I rescued them and chopped them up and produced the prototype version of this, as Lars is a chilli freak. The grapefruit quantities are approximate so if you have a couple extra, just use them and add a little more water to cover.
The skins from about 4 grapefruits
500g preserving or granulated sugar
2-3tsp dried chilli flakes
About 200g granulated sugar for coating
Quarter the grapefruit halves if you have used them for juicing and cut away any flesh that is left and discard it, so you are left with just the skin and pith. Cut into long strips about cm wide and put them in a saucepan.
Cover with water and bring to the boil and drain. Do this once more, then put them back in the saucepan with the preserving sugar and chilli and cover with water.
Bring to the boil and simmer on a medium heat for about 40 minutes, stirring every so often until the syrup is thick. Drain in a colander over a bowl for about 30 minutes, stirring the grapefruit so that all of the syrup has drained off. Save the syrup for your next batch or as a savoury sweet syrup for pancakes.
Lay the pieces of grapefruit on a cake rack and leave to dry out at room temperature for 3-4 days, then roll them in the granulated sugar and store in an airtight container.