Place the salt and all the herbs into a food processor and process until the salt is pure green. Set aside.
Place the turkey breasts on a wire rack above a sheet pan and place in the refrigerator to dry for 3 hours. Take out and rub the salt all over the turkey breasts. Return to the refrigerator for another 2 hours. Take out and rinse all the salt off in cold running water.
Place back on a clean rack on a sheet pan and let sit overnight in the refrigerator.
Preheat the oven to 250 degrees F.
Take the turkey out and place, skin side up, in a deep hotel pan. Cover the turkey completely in the duck fat. Roast in the oven for 3 hours. When it comes out, let it sit for 1 hour to cool off.
