01 - Preheat your oven to 375°F (190°C). Cut off the tops of the bell peppers and meticulously remove the seeds and membranes. Lightly coat the outer surfaces of the peppers with 1 tablespoon of olive oil. Arrange the prepared peppers upright in a baking dish.
02 - In a saucepan, warm the remaining 1 tablespoon of olive oil over medium heat. Introduce the finely chopped red onion and minced garlic to the pan, sautéing for 2 to 3 minutes until their fragrance is released.
03 - Add the diced zucchini to the saucepan and continue to cook for 3 to 4 minutes until it begins to soften.
04 - Incorporate the rinsed quinoa, ground cumin, smoked paprika, chili powder, salt, and black pepper into the saucepan. Toast the mixture for 1 minute, stirring constantly. Pour in the vegetable broth, bringing the liquid to a boil. Reduce the heat, cover the saucepan, and allow it to simmer for 15 minutes, or until the quinoa is fully cooked and all the liquid has been absorbed.
05 - Remove the saucepan from the heat. Gently stir in the drained and rinsed black beans, drained corn, and chopped baby spinach. Ensure all the components are thoroughly combined.
06 - Carefully spoon the prepared quinoa mixture into each of the hollowed-out bell peppers, filling them to the brim.
07 - If using, sprinkle the shredded cheddar or Monterey Jack cheese evenly over the top of each stuffed bell pepper.
08 - Cover the baking dish securely with aluminum foil. Place the dish in the preheated oven and bake for 30 minutes. Following this, remove the foil and continue baking for an additional 10 minutes, or until the peppers are tender and any added cheese is beautifully melted.
09 - Garnish the finished stuffed peppers with fresh chopped cilantro, if desired. Serve immediately with lime wedges on the side.