Set your oven to 400°F. Use an oven-safe skillet if you have one.
Use a sharp knife to cut a pocket into each chicken breast. Don’t cut all the way through.
In a small bowl, stir together salt, paprika, garlic powder, onion powder, and black pepper.
In a bowl, mix broccoli, red bell pepper, cheese, mayo, and 1 teaspoon of the seasoning.
Fill each chicken pocket with the veggie-cheese mix. Secure with toothpicks.
Sprinkle the rest of the seasoning on both sides of the chicken.
Heat olive oil in your skillet. Sear the chicken for 3–4 minutes per side until browned.
Put all chicken into the skillet, cover with foil, and bake for 18–20 minutes. Chicken should be 165°F inside.
Let the chicken rest for 5 minutes. Remove toothpicks before eating.