Add the basil, cashews, and garlic to a mini-chopper. Pulse until the whole mixture is finely chopped. Remove the blade, and scrape the mixture into a glass jar.

Using a fork (I like that it acts as a rake pulling the ingredients together), stir in the cheese and olive oil. Season with salt, to your liking, and stir again until well mixed. The pesto is ready to use immediately.

For longer term storage in the fridge, add enough oil to completely cover the pesto. You can also divide the pesto into ice cube trays and freeze it for single serve portions.