01 -
Cut each chicken breast horizontally so it opens up like a book, staying connected on one side.
02 -
Sprinkle the insides with salt, pepper, and thyme. Layer a few pieces of spinach or arugula on one side of each breast. Top with about 3 apple slices and 3 brie slices per chicken breast.
03 -
Fold each chicken breast over to close it up. You can use toothpicks to secure them if you want, but it's not necessary.
04 -
Mix both mustards together in a small bowl. Brush half of the mixture on top of the closed chicken breasts.
05 -
Heat the olive oil in a large skillet over medium-high heat. Place the chicken breasts mustard-side down in the pan. Brush the other side with the remaining mustard mixture.
06 -
Sear for 3 to 4 minutes on each side until nicely browned. Flip carefully so the filling stays inside.
07 -
After both sides are browned, cover the pan and reduce heat to just under medium. Cook for 5 to 8 minutes more, depending on thickness, until the chicken is cooked through.
08 -
Plate the chicken breasts and spoon the pan sauce over the top. Serve hot.