01 - Preheat oven to 400°F. Line a baking sheet with parchment paper or lightly grease the surface.
02 - In a small bowl, blend together garlic powder, paprika, salt, and black pepper. Set aside.
03 - Pat chicken breasts dry with paper towels. Using a sharp knife, cut a deep pocket into each breast without slicing through.
04 - Rub each chicken breast with olive oil and generously apply the prepared seasoning mix to the exterior and interior pockets.
05 - In a separate bowl, thoroughly combine chopped broccoli, shredded cheddar cheese, cream cheese, grated Parmesan, Dijon mustard, and minced garlic.
06 - Fill each chicken breast pocket with the broccoli-cheese mixture, securing the opening with toothpicks if necessary.
07 - Place the stuffed chicken breasts onto the prepared baking sheet, seam side up.
08 - Bake in the preheated oven for 25 to 30 minutes, or until internal temperature reaches 165°F and cheese is bubbling.
09 - Let the chicken rest for 5 minutes before serving. Carefully remove any toothpicks prior to plating.