Place the water, cashews, lemon juice, vinegar, granulated onion, and granulated garlic into a blender, set aside for at least 15 minutes so the cashews can soften.
Blend until very smooth, adding a little water as needed.
Add the green onion and dill, and blend for just a few more seconds so that you can still see green flecks in the dressing.
Refrigerate for 2-3 hours or overnight for the best flavor. Store leftover dressing in a covered container in the refrigerator for up to five days and shake before using. If the dressing is too thick, stir in a little water.
