Add the water to a medium pot and bring to a boil. Add the rinsed quinoa, cover with a lid, reduce heat, and simmer for 15 minutes or until all the water is absorbed.
Meanwhile, prep the bell peppers. Cut the tops off of the bell peppers and set them aside, and remove the seeds and fleshy ribs from inside the pepper. You should be left with a hollow cavity perfect for stuffing.
Fill a large pot with 1-2 inches of water and place a steamer basket in the pot. Place the bell peppers with their tops into the steamer basket and cover the pot with a lid. Bring to a boil, then reduce heat to a simmer and steam the peppers for about 7-10 minutes or until tender.
Heat a large skillet over medium high heat. When hot, add the onions and garlic and sauté until translucent, adding a tablespoon of water as needed to prevent the onions and garlic from sticking to the pan.
Add the cooked quinoa, black beans, chopped spinach, salt, and pepper to the skillet with onions and stir until everything is combined and the spinach is lightly wilted.
Stuff the peppers with the quinoa stuffing mixture and serve immediately.
The calorie count for this recipe is approximate and should only be used for informational purposes.