Season the quinoa with salt and pepper in a saucepan. Add the recommended water according to the instructions on the package and cook using the instructions. Once done keep covered with a lid to keep warm
Heat a non-stick pan over medium heat. Once hot, add the oil and brown the beef in the pan with the taco seasoning (to taste), breaking it up into smaller pieces until it is no longer pink. Add in the beans and a few tablespoons of water, reduce the heat to medium low. Season with salt and pepper to taste. Let simmer until the flavor concentrates. Stir in 1/2 of the cheese until melted.
In a bowl mix the tomatoes, onion, cilantro, lime juice and season with salt and pepper.
Spoon the beef mixture over the quinoa, top with avocado, tomato mixture, and remaining cheese. Garnish with cilantro. Serve with chips and sour cream if desired.