To cook quinoa, rinse in a strainer under cool water then transfer to a rice cooker. Mix in vegetable broth and cook.
To make the sauce, place all ingredients into a blender and mix until smooth and creamy. Depending on desired consistency, you may need to add more water, lemon juice, or tahini. Taste and adjust seasoning, if needed.
To serve, divide mixed greens portions out and make a bed at the bottom of each bowl. Place quinoa portions on top, then top with the desired amount of cucumber, tomato, red onion, green onion, and olives. Drizzle with cashew tzatziki sauce.
Notes
Store leftovers in the refrigerator for up to one week.