1/2 cup peeled and diced apple
1/4 cup chopped pecans
1 tablespoon finely chopped fresh sage leaves
1 teaspoon fresh thyme leaves
2 ounces thinly sliced Brie cheese
1 (2- to 3-pound) boneless turkey breast
1 tablespoon unsalted butter, cubed
Freshly ground pepper
Preheat the oven to 425°F. Line a rimmed baking sheet with foil or parchment paper and set aside.
Combine the apples, pecans, sage, and a pinch of salt and pepper, in a small bowl.
Pat the turkey breast dry. Using a sharp knife, make a deep slit along the meatiest side, cutting far into the breast with your knife parallel to the cutting board to create a pocket (don't slice all the way through).
Layer the slices of Brie inside the pocket, then use your hands to push the stuffing on top of the cheese. Stick three to four toothpicks through the open edges of the turkey to keep the stuffing from falling out.
Loosen the skin on the turkey breast and use your fingers to push the butter under the skin. Spread the skin back out across the breast, and sprinkle liberally with salt and pepper. Place on the prepared baking sheet.
Bake for 40 to 50 minutes, until the skin is brown and crispy, and an instant-read thermometer inserted in the thickest part of the breast reads 165°F. Remove the turkey from the oven and rest for about 5 minutes. Remove toothpicks, and then slice the turkey to serve.