Cook the Quinoa: In a medium saucepan, combine 1 cup of rinsed quinoa and 2 cups of water. Bring to a boil, then reduce heat to low, cover, and simmer for 15 minutes or until the water is absorbed. Fluff with a fork and set aside to cool.
Prepare the Vegetables: While the quinoa cooks, chop the cherry tomatoes, red bell pepper, avocado, red onion, and cilantro. Set aside in separate bowls.
Mix the Dressing: In a small bowl, whisk together the juice of 2 limes, cumin, salt, and pepper. Adjust seasoning to taste.
Combine Ingredients: In a large bowl, combine the cooked quinoa, black beans, cherry tomatoes, red bell pepper, and red onion. Pour the lime dressing over the mixture and toss gently to combine.
Serve or Store: Divide the quinoa and black bean mixture into meal prep containers. Top each serving with diced avocado and chopped cilantro just before eating to maintain freshness.