Add the raw cashews, water, lemon juice, apple cider vinegar, minced onion, dill, parsley, garlic, and salt to the container of a high-speed blender. Blend until completely smooth. Taste and add more salt, if needed.
Transfer the dip to a covered bowl and refrigerate for at least an hour.
Before serving, garnish with green onions or chives, if desired.
Even if you have a high-speed blender such as a Vitamix, it's easier to blend the cashews if you cover them in water and let them soak in your refrigerator for an hour or more. Then drain them before adding them to the blender.Serve this dip with your favorite potato chips and raw or roasted veggies. Store leftover dip covered in the refrigerator for up to a week.