1. Cook the quinoa: In a saucepan, bring 2 cups of water to a boil. Add the quinoa, reduce heat to low, cover, and simmer for about 15 minutes or until the water is absorbed. Fluff with a fork and let it cool.
2. Prepare the vegetables: While the quinoa is cooking, chop the cherry tomatoes, bell pepper, red onion, cilantro, and avocado. Set aside.
3. Mix the salad: In a large mixing bowl, combine the cooked quinoa, black beans, corn, cherry tomatoes, bell pepper, red onion, cilantro, and avocado. Toss gently to mix.
4. Add the dressing: Pour the lime juice over the salad and toss again to coat evenly.
5. Serve: Top with shredded cheese and salsa. Serve immediately or chill in the fridge for later.