Prep the peppers. Heat oven to 375°F (190°C).
Slice a thin piece off the bottom of each pepper if needed so they stand upright. Place them cut-side up in a baking dish. Drizzle with a little olive oil and a pinch of salt.
Soften the shells. Add 1/4 cup water to the bottom of the dish.
Cover tightly with foil and bake for 12–15 minutes until slightly tender. This step helps the peppers cook through without drying out.
Brown the protein. While peppers bake, heat 1 tablespoon olive oil in a large skillet over medium-high heat. Add ground turkey (or chosen protein).
Cook, breaking it up with a spoon, until browned and cooked through, 5–7 minutes. Drain excess fat if needed.
Build the flavor base. Add onion and cook until softened, 3–4 minutes. Stir in garlic and cook 30 seconds, just until fragrant.
Season well. Sprinkle in chili powder, cumin, smoked paprika, oregano, salt, and black pepper.
Stir for 30–60 seconds to bloom the spices. Taste and adjust salt if needed.
Mix the fillings. Stir in rice or quinoa (if using), black beans, and corn. Add salsa and broth. Simmer 2–3 minutes until slightly thickened but still juicy.
Finish with lime juice. The mixture should be moist enough to spoon easily, not soupy.
Stuff and top. Remove peppers from the oven. Spoon the filling evenly into each pepper, packing it gently.
Sprinkle about half the cheese over the tops.
Bake to finish. Return the dish to the oven, uncovered, and bake 12–15 minutes, until peppers are tender and cheese is melted and bubbling. For a golden top, turn on the broiler for 1–2 minutes at the end.
Garnish and serve. Let peppers rest 5 minutes. Top with remaining cheese if you like a stretchier finish, then add cilantro and any optional toppings—avocado, jalapeños, a dollop of Greek yogurt, and hot sauce.