Preheat your oven to 200°C (390°F). Cut the tops off the bell peppers, remove seeds, and place them on a parchment-lined baking sheet. Lightly brush the outside with olive oil. Roast for about 20 minutes until slightly softened and charred at the edges, which adds smoky flavor.
While the peppers roast, heat a tablespoon of olive oil in a large skillet over medium heat. Add the diced onion and sauté for about 5 minutes until fragrant and translucent, with a slight golden hue.
Add the minced garlic to the skillet and cook for another minute until fragrant, filling the kitchen with a warm aroma.
Stir in the cooked quinoa, rinsed black beans, tomato paste, smoked paprika, and chili powder. Cook for another 5 minutes, stirring often, until the mixture is fragrant, slightly saucy, and well combined.
Taste the filling and season with salt and pepper as needed. Remove from heat and let it cool slightly to prevent sogginess in the peppers.
Once the peppers are roasted and cool enough to handle, use a spoon or scoop to stuff each pepper generously with the quinoa mixture. Press gently to pack the filling in tightly.
Arrange the stuffed peppers upright on the baking sheet and bake for an additional 15–20 minutes at 180°C (355°F) until bubbling around the edges and the peppers are tender with slight charring on top.
Remove from the oven, garnish with chopped cilantro, and let rest for 5 minutes. This allows the flavors to meld and makes them easier to serve.
