Preheat the oven to 375. Place cut and cleaned bell peppers in a baking tray. Brush with a little bit of olive oil. Set aside.
Over medium-high heat in a non-stick pan with olive oil, cook the onions until translucent, 4-5 minutes. Add the ground beef and cook until just browned. Add spices and stir until combined.
Add cooked quinoa, corn, shredded cheese, black beans, and salsa. Stir until mixed.
Add mixture to the cavity of your bell peppers. Cover with aluminum foil and bake for about 20 minutes. Remove the foil, add more cheese, and bake for another 5 minutes or until cheese is melted. Serve with sour cream, extra cheese, chips, and salsa.