Wash sweet potatoes and poke with a fork. Bake in the oven at 400 degrees F for 40 minutes, or microwave for 5 minutes for first potato and 3 minutes for each additional potato.
When potatoes are cooked, slice in half and scoop out most of the potato, and save for another recipe. Leave a little in the skin.
Rinse quinoa well. Add 2 cups of water with quinoa and cook either on the stove top on medium for about 15 minutes, or in a rice cooker.
While quinoa cooks, dice pepper, onion, mince garlic and drain and rinse beans.
When quinoa is cooked, combine with remaining ingredients, juicing the limes and adding to the mixture.
Stuff potatoes with quinoa mixture.
Sprinkle with cheese if desired, and broil in the oven until cheese is melted and golden. (1-2 minutes)