Preheat a grill to medium heat.

Cut the tops off the bell peppers and remove the seeds and membranes. Set aside.

In a large bowl, combine the ground beef, diced onion, garlic powder, smoked paprika, dried oregano, salt, and pepper. Mix until well combined.

Divide the ground beef mixture evenly among the bell peppers, stuffing the mixture into each pepper.

Top each bell pepper with shredded cheddar cheese.

Place the bell peppers on the preheated grill and cook for 20-25 minutes, or until the beef is cooked through and the peppers are tender.

Remove the bell peppers from the grill and let them rest for a few minutes.

Garnish the stuffed bell peppers with chopped fresh parsley and serve hot.