There's a jar that is always in our fridge - Cured lemons. We put them on almost everything, and every time someone tastes them for the first time they ask for the recipe. So we finally wrote it down.

It comes from Honey & Co in London, Itamar and Sarit, the first people in the UK to sell our knives and among the first to actually cook with them every day. This is their quick cured lemon from their first book, with one change: we swapped the chilli for harissa for a rounder, gentler heat. Over the years we also worked out a fermented version, so the recipe now comes two ways. A quick one that's ready in 24 hours, and a slow ferment that gets deeper and smoother the longer you leave it. Both earn their place on the shelf.

Ingredients

4 lemons
3 tbsp sea salt
1 tbsp harissa

Preparation

1. Halve the lemons — 8 halves total — then slice each half thinly. Combine with the salt and harissa powder and mix well. Let sit in a bowl at room temperature for about 30 minutes, or until the juices start to come out (a bit longer in a cool room is fine). Want more heat? Add chilli flakes, urfa chilli flakes for a smokier edge, or any fresh or dried chilli you like.
2. Pack tightly into a clean jar, pressing down so the juices rise and cover all the slices.

Quick version (24 hours):

Leave in a shaded spot at room temperature. The next day, blend or food-process into a smooth paste.

Fermented version (10+ days):

Keep in a cool, shaded place. Open the jar once a day for the first 3–4 days to release the gases, then leave it undisturbed for another week or so. The longer it ferments, the deeper and smoother the flavour. Once opened, store in the fridge. Use blended as a paste, left whole, or chopped.