01 - Preheat oven to 400°F. Line a baking sheet with parchment paper or lightly grease the surface.
02 - Combine garlic powder, paprika, salt, and black pepper in a small bowl. Set aside.
03 - Pat chicken breasts dry. Using a sharp knife, cut a pocket lengthwise into each breast without slicing through completely.
04 - Rub each breast with olive oil and apply the seasoning blend, including inside the pocket.
05 - In a mixing bowl, combine chopped broccoli, shredded cheddar, cream cheese, Parmesan, Dijon mustard, and minced garlic. Stir until fully incorporated.
06 - Stuff each chicken breast generously with the prepared broccoli-cheese mixture. Secure openings with toothpicks if necessary.
07 - Place stuffed chicken breasts on the prepared baking sheet. Bake for 25 to 30 minutes, or until the internal temperature reaches 165°F and the filling is bubbling.
08 - Allow the chicken to rest for 5 minutes after baking. Remove toothpicks before serving.