Bring quinoa, broth and salt to a boil in a saucepan. Reduce heat to medium-low, cover, and simmer until the quinoa is tender, 16-22 minutes. Meanwhile, stir together the lime juice, olive oil, pepper, garlic, onion, diced tomatoes, and beans. When the quinoa is done, stir it into the tomato mixture, then cool in refrigerator until cold, about 2 hours
When the quinoa is cold, fluff with a spoon, and gently fold in the cilantro/parsley, avocados, and cheese.