Add the cashews, lemon juice (if using) water and salt (if using) to the blender jug and blend until smooth.
The basic cream recipe is really just the cashews and water. If you want a thinner cream then use up to a ¼ cup more water.
The lemon juice and salt add a tang and a little savory flavor, though it’s mild. It makes this stand out more as a standalone recipe ready to use as is.
If you are really wanting just the blank slate recipe to use in another recipe or to closely match unflavored dairy cream, then start with just the cashews and water only.