In a large pot cook red onion and garlic scapes over medium 3 minutes, stirring occasionally and adding broth, 1 to 2 tablespoons at a time, as needed to prevent sticking. Add remaining broth and the next five ingredients (through crushed red pepper). Increase heat to high. Bring to boiling; reduce heat. Cover and simmer 30 to 35 minutes or until vegetables are very tender. Cool slightly. Working in batches, transfer soup to a blender; cover and blend until smooth. Season with black pepper.

In a small blender or food processor combine cashews, garlic powder, onion powder, and dry mustard. Blend until smooth, gradually adding milk until cashew cream is about the same consistency as the soup.

Ladle soup into bowls. Top each serving with 2 tablespoons cashew cream. Garnish with microgreens or radish sprouts if desired.