Cut the tops off the bell peppers and remove the seeds and membranes. Set aside.
In a large skillet, heat olive oil over medium heat. Add the chopped onion and garlic, sautéing until the onion is translucent, about 5 minutes.
Add the ground chicken to the skillet, breaking it apart with a spoon. Cook until browned and cooked through, approximately 7-10 minutes.
Stir in the cooked quinoa, black beans, corn, diced tomatoes, chili powder, cumin, smoked paprika, salt, and pepper. Mix until well combined and heated through, about 5 minutes.
Spoon the chicken mixture into each of the bell peppers, pressing down lightly to pack them in.
Place the stuffed peppers in a baking dish, and sprinkle the shredded cheese evenly on top of each pepper.
Cover the baking dish with aluminum foil and bake in the preheated oven for 25 minutes.
Remove the foil and bake for an additional 10 minutes, or until the cheese is melted and bubbly.
Remove from the oven and let cool for a few minutes. Garnish with fresh cilantro if desired before serving.
Notes
Serve these colorful stuffed peppers on a platter, drizzled with a bit of olive oil and sprinkled with fresh cilantro for an extra pop of color!