Using a standing blender or an immersion blender and deep cup or jar, puree all the ingredients (starting with 1⁄2 cup of the water). Start on a slow speed to incorporate the cashews, then increase speed to high until very smooth and creamy. Add additional water to thin, as desired, and salt, agave, and chipotle sauce to taste. Dollop on soup, or use as a dip with tortilla chips.