*Soaking cashews bring out the creamiest of textures. Simply put them in a bowl, cover with water, place a cover on the bowl, and let sit on the counter overnight or for at least 4 hours. (If you let them sit longer than overnight, refrigerate). When ready to use, simply drain.
If you forget to soak them, you can still make the pesto, but note that it will have a much different texture, and won't be as creamy.