Brown your beef in a large skillet, along with your diced onion. Once the onion is translucent and the beef is browned, drain off the fat in a colander. Put it back in the skillet and add in your seasonings. If you are using taco seasoning, add that in with about a ½ cup of water in the bottom of the skillet. Otherwise just season with onion powder, garlic powder, ½ lime, and salt + pepper.
Start cooking your quinoa in the water (about 3 cups) over medium heat. I like to pre-soak my quinoa for about 15-30 minutes in a measuring cup. Then add it to boiling water until the quinoa is completely cooked through. Rinse again and drain.
In a 9 x 13 glass pan add the quinoa mixture to the bottom and squeeze 1 full lime overtop. Sprinkle salt over the quinoa and layer the cheese, beef, and cilantro. Keep out about ¼ cup of cilantro for the topping.
Bake for 10 minutes at 350 or until the cheese has melted all of the way through.
Top with sliced avocados, guacamole, salsa, and the rest of the cilantro. Squeeze 1 /2 lime overtop and enjoy! You can add some black pepper here if you want, totally optional.
