1. Rinse the quinoa in cold water. Boil water in a saucepan, and then add the quinoa.
2. Return to boil, and then simmer until the water is absorbed, 10 to 15 minutes.
3. Cool for 15 minutes. While quinoa is cooking, mix olive oil, lime juice, cumin, coriander, chopped cilantro, and scallions in a small bowl, and set aside.
4. Combine chopped vegetables with the black beans in a large bowl, and set aside.
5. Once quinoa has cooled, combine all ingredients and mix well. Cover and refrigerate until ready to serve.