Add all ingredients to a food processor with the knife blade attachment in place. Turn on and process until the mixture is blended to a very fine mixture. You may have to scrape the sides from time to time. About 3 minutes.
Pour the salt mixture onto a baking sheet and gently shake it to distribute evenly. Let dry for 3 days at room temperature. You could add the mixture back to the food processor to break it up before storing.
Store in an air-tight container in a cool, dry location.