Preheat the oven to 350°F (175°C).

Cook the quinoa by combining quinoa and broth in a medium pot. Bring to a boil, cover, and reduce heat to low. Cook for 15 minutes.

Remove from heat and let the quinoa sit covered for 5–10 minutes. Fluff with a fork and set aside.

Wash and dry the bell peppers. Slice them in half lengthwise and remove the seeds and membranes.

Drizzle olive oil over the peppers and season with salt and pepper.

Place the peppers cut-side up in a 9×13 baking dish and bake for 15–20 minutes until slightly softened.

Meanwhile, prepare the filling. Heat olive oil in a large skillet over medium heat.

Add the diced onion and jalapeño and sauté for about 2–4 minutes until softened.

Add the minced garlic and cook for about 30 seconds until fragrant.

Stir in the cooked quinoa, diced tomatoes, black beans, garbanzo beans, corn, green chiles, taco seasoning, salt, and pepper.

Cook for a few minutes until everything is heated through. Taste and adjust seasoning if needed.

Spoon the filling into the softened bell peppers.

Sprinkle shredded Mexican cheese evenly over the tops.

Return the baking dish to the oven and bake uncovered for another 15 minutes until the peppers are tender and the cheese is melted.

Garnish the Quinoa Stuffed Bell Peppers with cilantro, avocado, sour cream, or lime before serving if desired.