In a medium skillet, begin by sautéing the garlic and onions in the olive oil and butter for a minute or two.
Add the bread crumbs; toss until they begin to brown slightly.
Add the hazelnuts, thyme, cranberries, salt and pepper.
Add only enough turkey stock to make the stuffing hold together.
Place the first pastry sheet on a parchment lined cookie sheet.
Place the turkey breast along the center line of the pastry sheet.
Brush the edges of the pastry with the egg wash.
Place the stuffing on top of the turkey.
Place the second pastry sheet over the turkey and stuffing,
Trim the edges to form an oval shape; save the trimmings in the refrigerator.
Bring the edges of the dough together by pinching them to seal.
Roll the dough from the bottom layer over the top layer and press down all the way around the perimeter of the pastry; this creates a tighter seal.
Brush the egg wash over the entire surface of the pastry.
Decorate with additional pastry leaf shapes, if desired, by cutting leaf shapes out of the trimmed pastry and score leaf veining into them with the tip of a sharp knife.
Cut four 1/2-inch slots in the top of the pastry to let steam escape.
Chill for 20 minutes or longer in the refrigerator before baking; this helps the pastry to puff.
Pre-heat oven to 400°F.
Remove from the refrigerator; place in the pre-heated oven and bake for about 15 to 20 minutes; reduce the heat to 350°F.
Contiune to cook about 35 to 45 minutes longer; use a meat thermometer to make sure that the center has reached at least 170°F to ensure the turkey is completely cooked.
Remove from the oven; let rest for 10 minutes before cutting into individual servings.