Preheat oven to 325 degrees. Place the 8-10 lb turkey breast In a small bowl, whisk together 3 tablespoons olive oil, 1/2 teaspoon salt, 1/2 teaspoon pepper, and 1 teaspoon poultry seasoning. Rub the seasoning and oil mixture over the turkey, both outside and under the skin.
Roast, uncovered for 30 minutes. Meanwhile, in a medium bowl, mix 2 cups chicken broth, 1/4 cup fresh parsley, 1/2 teaspoon dry thyme, 1/2 teaspoon dry rosemary, 1/2 teaspoon herbs de provence, zest and juice of 1 lemon, and 2 cloves garlic, minced.
Pour the mixture over the turkey and roast, uncovered, for 2 1/2 to 3 hours (about 20 minutes per pounds), or until a thermometer inserted in the thickest part of the breast reads 165 degrees. Baste occasionally with the juices during cooking.
Remove the turkey from the pan and let stand for 15-20 minutes. Skim the fat from the cooking juices.
Carve the turkey and place in shallow freezer containers. Pour the cooking juices over the turkey and let cool for another hour. Cover and freeze for up to 3 months.
To thaw and reheat: place the turkey in the refrigerator overnight. Preheat oven to 350 degrees. Transfer the turkey and the juices to a baking dish. Pour an additional 1 1/2 cups broth over the turkey. Cover and bake for about an hour, or until the internal temperature reaches 165 degrees.
To make the gravy: melt the butter in a saucepan over medium heat, then stir in the flour until smooth. Gradually whisk in the cooking juices from the turkey. Bring to a boil, whisking constantly, until gravy is thickened and bubbly.