Add chopped potatoes and cauliflower and cook until both are fully cooked (about 12-15 minutes).
While vegetables are cooking, add cashews and water to a high-speed blender and blend until smooth.
When cauliflower and potatoes are cooked, drain them and add them back to pot. Add the cashew cream and the rest of the ingredients (except chives) to pot and use a hand mixer to combine until creamy. If you don't have a hand mixer add everything to a stand-alone blender and blend until creamy.