Blend. Add the cashew butter, water, lemon juice, capers, caper brine, mustard, maple syrup, garlic clove, and a pinch of salt to a blender or food processor. Blend until smooth. Alternatively, add everything to a bowl and blend with an immersion blender.
Adjust the amount of lemon juice and caper brine to taste to taste. Add more water to make the dressing thinner if needed
Transfer the dressing to an air-tight container and store it in the refrigerator for up to 1 week.
Notes
You can also use raw cashews instead of cashew butter. Use the same amount in grams. Soak them in water for 2 hours or boil them for 30 minutes while roasting the garlic, then follow the same instructions. Add more water if needed.