1. Preheat your oven to 375°F (190°C). Line a baking sheet with parchment paper for easy cleanup.
2. Cut the bell peppers in half lengthwise and remove the seeds and membranes. Arrange them on the prepared baking sheet, cut side up.
3. In a large skillet over medium heat, add the olive oil. Sauté the onion and garlic until fragrant and the onion is translucent, about 3-4 minutes.
4. Add the ground beef or turkey to the skillet, breaking it apart with a wooden spoon. Cook until browned, about 6-8 minutes. Drain any excess fat if necessary.
5. Stir in the taco seasoning, black beans, and corn. Cook for another 2-3 minutes until everything is well combined and heated through. Season with salt and pepper to taste.
6. Spoon the meat mixture evenly into each bell pepper half. Top with shredded cheddar cheese and sliced jalapeños if using.
7. Bake in the oven for 15-20 minutes, or until the peppers are tender and the cheese is bubbly and golden.
8. Garnish with chopped cilantro and serve with sour cream and guacamole on the side.

I love involving my kids in this step—they enjoy sprinkling the cheese and arranging the toppings, making it a fun family activity.