Soak cashews in hot water for 15 minutes or room temperature water for 4 hours. Drain water.
Add cashews to a high speed blender along with the rest of ingredients. Blend until smooth and creamy.
Notes
Start with less apple cider vinegar and dry mustard. I like it tangy, but you may want less.This recipe will last about 1 week in an airtight container in the fridge.