In a mixing bowl, combine the chopped broccoli, cream cheese, cheddar cheese, Parmesan cheese, minced garlic, onion powder, salt, and pepper. Mix until well combined.
Carefully slice a pocket into each chicken breast, ensuring you do not cut all the way through.
Stuff each chicken breast with the broccoli mixture, using toothpicks to secure the opening if necessary.
Season both sides of the stuffed chicken breasts with salt, pepper, and paprika.
Heat olive oil in a large oven-safe skillet over medium-high heat. Once hot, sear the stuffed chicken breasts for about 4-5 minutes on each side until golden brown.
Transfer the skillet to the preheated oven and bake for an additional 20-25 minutes, or until the chicken is cooked through and juices run clear (internal temperature should reach 165°F or 74°C).
Remove from the oven and let rest for a few minutes before slicing.
Notes
Serve on a platter with olive oil and parsley for garnish. Pair with roasted vegetables or salad.