Cut the tops off the bell peppers and remove the seeds and membranes. Set aside.
In a medium saucepan, bring the vegetable broth to a boil. Add the rinsed quinoa, reduce heat to low, cover, and let it simmer for about 15 minutes, or until all the liquid is absorbed.
In a large mixing bowl, combine the cooked quinoa, cherry tomatoes, chickpeas, olives, oregano, basil, garlic powder, salt, and pepper. Drizzle with olive oil and mix well until all ingredients are evenly coated.
Stuff each bell pepper with the quinoa mixture, packing it tightly.
Place the stuffed peppers upright in a baking dish. If desired, sprinkle crumbled feta cheese on top of each pepper.
Cover the dish with aluminum foil and bake in the preheated oven for 30 minutes. Then, remove the foil and bake for an additional 10-15 minutes, until the peppers are tender and lightly browned on top.
Remove from oven and let cool for a few minutes before serving. Garnish with fresh parsley.