1. Preheat oven to 425°.
2. In a medium sauté pan, melt the butter. Add onions, celery, carrots, cranberries and sage. Sauté until the onions are translucent.
3. In a large mixing bowl, combine the vegetable mixture with the brown sugar, salt, pepper, nutmeg, walnuts and cornbread stuffing. Stir in the vegetable stock.
4. Using a sharp knife, butterfly the turkey breast open. Lay flat on a cutting board, cover with plastic wrap. Pound the breast to a 1/2-inch thickness, creating a 10" x 15" rectangle.
5. Spread the stuffing evenly onto the breast and then roll the breast from one tip of the breast to the other side to form an even roulade. Tie the turkey roulade with 7 pieces of twine.
6. Rub with vegetable oil; evenly sprinkle with salt, pepper and parsley flakes.
7. Place on a baking sheet. Bake at 425° for 25 minutes. Reduce the heat to 350° and bake for another 30 minutes or until it reaches an internal temperature of 165°.
8. Allow the turkey to rest 10 minutes, remove the twine and gently carve 1/2-inch slices of the roulade.