Add in your diced onion and sauté for 2 minutes, or until it softens a bit. Add in the ground beef, garlic, and taco seasoning, then cook the meat until no longer pink. Mince the meat with a wooden spatula as it cooks.
Stir in the beans together with the chopped tomatoes, and green onions, then cook for 2-3 minutes more.
To Assemble Your Burritos:
Lay down all tortillas then equally to each add meat mixture, a good sprinkle of brown rice, shredded cheese, and a small dollop of mashed avocado.
Fold in the sides and roll up the burrito. Repeat with remaining wraps and fillings.
Heat up your same skillet over medium and cook your burritos flipping them on all sides, for 5-6 minutes in total, or until golden brown and nicely crisp.
Serve your burritos warm with shredded lettuce, fresh cilantro, Greek yogurt, and mashed avocado, if desired