Wash and thoroughly dry the basil leaves.

Pulse the basil and salt together in a food processor until fine and evenly mixed.

Spread the mixture in a thin layer on a parchment-lined baking sheet.

Let it air-dry for 24-48 hours, stirring occasionally, or dry it in the oven at the lowest setting (around 150 F) for about 15 minutes.

Once completely dry, pulse again or push through a sieve if you want a finer texture (it may clump).

Store in a cool dark place in an airtight jar for up to 3 months.