01 - Preheat oven to 400°F. Line a baking sheet with parchment paper or lightly grease the surface.
02 - In a small bowl, mix together garlic powder, paprika, salt, and black pepper until even.
03 - Pat chicken breasts dry with paper towels. Using a sharp knife, slice a pocket into each breast without cutting through.
04 - Rub each chicken breast with olive oil and coat thoroughly with the prepared seasoning, ensuring the inner pockets are also seasoned.
05 - In a separate mixing bowl, combine chopped broccoli, shredded cheddar cheese, softened cream cheese, grated Parmesan, Dijon mustard, and minced garlic. Stir until fully incorporated.
06 - Spoon the broccoli and cheese mixture evenly into the cavity of each chicken breast. Secure openings with toothpicks if necessary to prevent filling from spilling.
07 - Place the stuffed chicken breasts on the prepared baking sheet. Transfer to the oven and bake for 25 to 30 minutes, until the chicken reaches an internal temperature of 165°F and cheese is bubbling.
08 - Let the stuffed chicken rest for 5 minutes after removing from the oven. Carefully remove toothpicks before serving.