Preheat the oven to 350 degrees F and spray a 9×13 baking dish with olive oil spray. Slice each bell pepper in half lengthwise, removing the ribs and seeds before placing them into the baking dish in an even layer. Brush or spray each pepper with some olive oil, then season them with salt and pepper before baking for 15 minutes.
While the peppers are baking, heat a sauté pan over medium-high heat with 1 tablespoon of olive oil. Add the ground turkey, breaking it apart as it cooks for about 2-3 minutes until browned, then mix in 1 tablespoon of taco seasoning and cook for an additional 2 minutes before adding onions and garlic.
Once onions become translucent (about 2-3 minutes), sprinkle in the rest of the taco seasoning along with corn and black beans, cooking them together for another minute before stirring in salsa and brown rice.
Divide the filling evenly among the prepped bell peppers, topping each one with shredded cheese before returning them to the oven to bake for another 15 minutes until bubbly and golden.
Top your taco stuffed peppers with your favorite garnishes such as sour cream, salsa, chopped cilantro, lime wedges, and sliced avocado before serving warm.