1. Rinse the quinoa under cold water.
2. In a saucepan, bring water to a boil. Add quinoa, reduce heat, cover, and simmer for 15 minutes or until water is absorbed.
3. Remove quinoa from heat and let it sit, covered, for 5 minutes. Fluff with a fork.
4. In a large mixing bowl, combine cooked quinoa, cherry tomatoes, cucumber, bell pepper, and red onion.
5. In a small bowl, whisk together olive oil, lemon juice, salt, and black pepper.
6. Pour the dressing over the quinoa and vegetables. Toss to combine.
7. Garnish with fresh parsley before serving.