Place all ingredients in a blender and blend until smooth
Put in an airtight container and let set in the fridge overnight.
Serve!
Notes
you must soak the nuts even if you are using a high speed blender. It is part of the overall end flavor. You can soak the cashews overnight or boil them for 30 minutes if you forget. Caution, some blenders won't be able to get a smooth result due to their lack of power.
Do not use lemon in place of lime. Lime is the key to get the perfect flavor.
Do not sub the vinegar with another kind. Apple cider vinegar is sweeter and not as tangy. The distilled white is key for the final result. If you sub it, the flavor will change. Add more vinegar if you want it more tangy but dairy sour cream is more of a neutral than sour flavor.
This recipe makes 2 ½ cups. Serving size is ¼ cup.
To make a nut free version, you can try subbing silken tofu for the nuts. Do the same amount, so 1 ½ cups plus 2 tablespoons. Flavor won't be as good and creamy but if you are nut free it's a great option.