1. Rinse the quinoa under cold water.
2. In a saucepan, bring the water to a boil. Add the quinoa, reduce heat to low, cover, and simmer for 15 minutes or until water is absorbed.
3. Remove from heat and let it sit, covered, for 5 minutes. Fluff with a fork.
4. In a large mixing bowl, combine the cooked quinoa, black beans, corn, cherry tomatoes, avocado, and cilantro.
5. In a small bowl, whisk together the lime juice, olive oil, garlic, cumin, salt, and black pepper.
6. Pour the dressing over the quinoa mixture and toss to combine.
7. Serve immediately or chill in the refrigerator for later.