Clean the basil and dry well. Mince.
Place salt and basil into a blender or spice grinder. Process until salt is powdery and green leaves are totally gone, evenly distributed in the salt.
Spread the basil salt on a parchment lined baking sheet. The parchment makes it easier to collect the salt. Place pan in the oven. If you have a pilot, close the door and allow to sit overnight, otherwise, turn oven to lowest setting and let sit for 2 hours. Leave in the oven if the basil isn't dried out.
Salt will clump when it's dry. Place back into the blender or spice grinder and process till all clumps are gone.