Rinse the quinoa under cold water. In a saucepan, combine quinoa and water. Bring to a boil, then reduce heat to low, cover, and simmer for 15 minutes, or until water is absorbed.
In a large bowl, combine cooked quinoa, black beans, corn, and bell pepper.
Drizzle with lime juice, add salt and pepper, and toss gently.
Top with diced avocado and chopped cilantro before serving.
In a bowl, whisk together olive oil, lemon juice, minced garlic, oregano, parsley, salt, and pepper.
Place the chicken breasts in a resealable plastic bag and pour the marinade over the chicken. Seal the bag and refrigerate for at least 30 minutes (up to 4 hours).
Preheat your grill to medium-high heat. Remove the chicken from the marinade and discard the marinade.
Grill the chicken for about 6-7 minutes per side, or until cooked through (internal temperature should reach 165°F).