Steam: Place finely chopped broccoli and 2 tbsp of water in a microwave-safe bowl. Cover with plastic wrap and microwave on high for 2–3 minutes until tender. Drain well.
Prep Chicken: Slice each chicken breast horizontally to create a pocket, being careful not to cut all the way through.
Season: Rub the outside of the chicken breasts liberally with the Italian seasoning, garlic powder, onion powder, salt, and pepper.
The Mix: In a medium bowl, combine the steamed broccoli, cheddar, cream cheese, Dijon mustard, and minced garlic. Stir until well combined.
Stuff: Distribute the broccoli-cheese mixture equally into the chicken pockets. Secure the edges with toothpicks to keep the filling inside.
Sear: Heat olive oil in a large oven-safe skillet over medium-high heat. Sear the chicken for 2–3 minutes per side until browned.
Bake: Preheat oven to 400°F (200°C). Cover the skillet with foil and transfer to the oven. Bake for 20 minutes or until the internal temperature reaches 165°F (74°C).
Serve: Remove toothpicks before serving. Pair with a side salad, garlic green beans, or roasted potatoes.