Place all ingredients into a high-speed blender and process until completely smooth.
Taste and, if necessary, add salt and a few drops of lemon juice.
Refrigerate and use within 2 weeks.
If you’re using a regular blender, soak the cashews for a few hours in water to cover. Drain completely. Omit the 2 tablespoons of water from the recipe, adding a little only if needed to facilitate blending.