Preheat the oven to 375°F (190°C).
Prepare the broccoli filling by mixing the chopped broccoli, cream cheese, cheddar cheese, garlic powder, onion powder, salt, and pepper in a bowl.
Slice a pocket into each chicken breast to hold the filling.
Stuff each chicken breast with the broccoli mixture and secure the openings with toothpicks.
Heat olive oil in a skillet over medium-high heat. Sear each stuffed chicken breast for 3-4 minutes until golden brown.
Transfer the seared chicken breasts to a baking dish and bake for 25-30 minutes, or until the chicken is cooked through.
Remove from the oven and let the chicken rest for 5 minutes before serving.