Preheat the oven: Set to 375°F (190°C).
Lightly grease a baking dish large enough to hold the peppers upright.
Prep the peppers: Slice off pepper tops, remove seeds and membranes, and trim the bottoms slightly if needed so they stand upright (don’t cut through). Place them in the dish, open side up.
Soften the peppers (optional): For very tender peppers, cover the dish with foil and bake empty for 10 minutes. This step helps if you like them soft.
Sauté aromatics: Warm olive oil in a skillet over medium heat.
Add onion and cook 3–4 minutes until translucent. Stir in garlic for 30 seconds until fragrant.
Build the filling: Add shredded chicken, cooked rice or quinoa (if using), black beans, and corn. Sprinkle in smoked paprika, chili powder, salt, and pepper.
Stir in 3/4 cup BBQ sauce. The mixture should be moist but not soupy. Adjust seasoning.
Stuff the peppers: Spoon the filling into each pepper, packing gently and mounding slightly on top.
Drizzle a little extra BBQ sauce over each for added moisture and flavor.
Bake covered: Cover the dish with foil and bake for 20 minutes. This traps steam and helps the peppers cook evenly.
Add cheese: Remove foil, top each pepper with shredded cheese, and bake uncovered for 8–10 more minutes, until the cheese is melted and bubbly.
Finish and serve: Let rest 5 minutes. Garnish with chopped cilantro or green onions.
Serve with lime wedges and extra BBQ sauce if you like.