Rinse the quinoa under cold water using a strainer to remove bitterness.
In a medium saucepan, combine the quinoa and water (or vegetable broth). Bring to a boil, then reduce heat to low, cover, and simmer for about 15 minutes or until the quinoa is fluffy and the water is absorbed.
While the quinoa is cooking, prepare the dressing by whisking together olive oil, lime juice, cumin, salt, and pepper in a small bowl.
In a large mixing bowl, combine the cooked quinoa, chickpeas, diced red bell pepper, diced cucumber, halved cherry tomatoes, corn, finely chopped red onion, and chopped cilantro. Toss gently to mix.
Drizzle the dressing over the quinoa mixture and toss to coat evenly.
Serve the quinoa bowl in individual dishes, topped with sliced avocado.