01 -
Butterfly each chicken breast by slicing horizontally, leaving one side attached to open like a book.
02 -
Sprinkle the inside of each chicken breast with kosher salt, black pepper, and thyme.
03 -
Place a layer of spinach or arugula on one side of each chicken breast, then top with approximately 3 slices of green apple and 3 slices of brie cheese.
04 -
Fold the chicken breasts to enclose the filling, securing with toothpicks if needed.
05 -
In a small bowl, combine Dijon mustard and coarse ground mustard. Brush half of the mixture onto the tops of the chicken breasts.
06 -
Heat olive oil in a large skillet over medium-high heat. Place chicken breasts mustard side down and brush remaining mustard mixture on the uncovered side. Sear for 3–4 minutes per side until golden brown.
07 -
Cover skillet, reduce heat to just below medium, and cook for 5–8 minutes until chicken is fully cooked through.
08 -
Plate the chicken and drizzle remaining pan juices over the top before serving while hot.