Heat the oven to 170 degrees.
Wash and thoroughly dry the herbs.
Place half of the salt on a rimmed baking sheet. Cover the salt with the herbs. Add the remaining salt on top of the herbs. Place in the oven and bake for 6 hours, or until the herbs are thoroughly dried.
Remove the herb salt from the oven. Place the herb salt mixture into a food processor and blitz until smooth. Store in an airtight container.