Yuzu Kosho

Ingredients

• 6 unripe green yuzu (about 500 g whole), to yield 40 g zest
• 40 g hot green chillies, such as serrano or green bird's eye
• 16 g fine sea salt (20 percent of the combined zest and chilli weight)
• 1 tbsp yuzu juice, squeezed from the zested fruit, if needed

Before you cook

• Wash the yuzu under cold running water and dry each fruit completely with a clean towel.
• Pull off the small stem nub at the top of each yuzu.
• Put on disposable gloves before handling the chillies.
• Split the chillies lengthwise and scrape out the seeds and white ribs with the tip of a teaspoon.
• Sterilise a small glass jar and its lid in boiling water, then stand it upside down on a clean cloth to dry.

Steps

1. Grate the green zest from the yuzu on a microplane, stopping the moment you reach the white pith underneath.
2. Weigh the zest and note the figure, aiming for about 40 grams.
3. Chop the deseeded chillies as finely as you possibly can.
4. Weigh out chilli to match the zest exactly, gram for gram.
5. Weigh out salt equal to 20 percent of the combined zest and chilli weight, which is 16 grams for a 40 and 40 batch.
6. Tip the zest, chilli and salt into a mortar.
7. Grind with the pestle for 4 to 5 minutes until the mixture turns into a coarse, glossy green paste with no chilli chunks left.
8. Squeeze a tablespoon of juice from a zested yuzu and work it in only if the paste looks dry and crumbly.
9. Pack the paste into the sterilised jar and press it down firmly to knock out air pockets.
10. Seal the jar and refrigerate for at least 7 days so the salt draws out moisture and the raw heat mellows.
11. Taste after a week and grind in a pinch more salt if the paste tastes flat.
12. Keep sealed in the fridge for up to a year, always digging in with a clean dry spoon.