Cook quinoa and vegetable broth according to package directions. Once cooked, fluff with a fork, then allow to cool for at least 20 minutes.
Whisk dressing ingredients in a bowl: olive oil, lime juice, cumin, and red pepper flakes.
Assemble: Transfer quinoa to a large bowl. Add black beans, tomatoes, green onions, cilantro and avocado. Pour dressing over salad and stir gently to combine. Serve immediately.
