01 - Preheat oven to 400°F (200°C). Line a baking sheet with parchment paper or grease lightly.
02 - Combine garlic powder, paprika, salt, and black pepper in a small bowl and set aside.
03 - Pat chicken breasts dry. Using a sharp knife, cut a deep pocket into each breast without slicing all the way through.
04 - Rub each chicken breast with olive oil, then coat generously with the seasoning blend, including inside the pockets.
05 - In a mixing bowl, combine chopped broccoli, shredded cheddar, cream cheese, Parmesan, Dijon mustard, and minced garlic until thoroughly blended.
06 - Evenly stuff each chicken breast pocket with the cheese-broccoli mixture. Secure openings with toothpicks if needed.
07 - Place stuffed chicken breasts onto the prepared baking sheet.
08 - Bake 25 to 30 minutes until chicken is fully cooked and internal temperature reaches 165°F (74°C), with cheese filling bubbling.
09 - Let rest for 5 minutes before serving. Remove toothpicks prior to plating.