Preheat the oven to 375°F (190°C).
Prepare the stuffing by combining sliced apples and Brie.
Slice a pocket in each chicken breast, being careful not to cut all the way through.
Stuff each chicken breast with the apple and Brie mixture.
Season the outside of the chicken with salt, pepper, and thyme.
Heat olive oil in a skillet over medium heat and sear each stuffed chicken breast for 3-4 minutes on each side.
Transfer the seared chicken breasts to a baking dish and pour chicken broth around them.
Bake in the preheated oven for 20-25 minutes or until the chicken reads 165°F (75°C) internally.
Allow the chicken to rest for 5 minutes before serving.