Yuzu Kosho is the signature, spicy condiment from Japan made from the zest of the yuzu fruit, an aromatic Japanese citrus, that's fermented with fresh chiles and sea salt.
While Yuzu can be hard to find in the States, we can substitute any citrus zest to capture the bright flavors of this condiment paired alongside a spicy pepper. This paste is best made in a mortar and pestle to integrate and release the flavors, but can also be incorporated in a food processor.
about 10 citrus fruits, zested (lemons, oranges, limes, or yuzu) 1-3 red or green bird’s eye chiles or a spicy chile of your choice (seeded for less heat), minced
3-4 teaspoons citrus juice 1-3 teaspoons coarse sea salt
Pound the citrus zest, chiles, and salt in a mortar and pestle (like this, or this) or combine food processor, until it forms a paste. Add citrus juice and scrape into a small jar. Cover with a lid and let ferment a few days at room temperature, stirring daily. Make sure to scrape down the sides after each stir. Store in refrigerator for an additional 2 weeks to age. Best enjoyed within one year!