In a large stockpot, combine 4 cups of water, molasses, salt, pepper, and lemon. Heat until salt dissolves, remove from heat. Add the remaining 4 cups of cool water and 4 cups of ice.

Put turkey breast into a large container. When the brine mixture is completely cooled and pour over they turkey. If the turkey isn't completely covered by water add enough to fully submerge. Place in refrigerator for 12 hours.

Remove the turkey from the brine and drain on a wire rack set over a sheet pan. Discard the brine. Let sit room temperature for 30 minutes before patting dry with paper towels.

Add the butter and dried seasonings to the a small bowl and mix to combine. Loosen the skins and rub half the butter under the skin and around the turkey. Rub the remaining over the top of the skin.

Place the carrots, onion, garlic, and chicken stock in the bottom of the slow cooker. Place the turkey on top. Cook for 4 to 5 hours on LOW. Begin checking at 3 ½ hours for doneness. Once the turkey reaches 155 F degrees move it to a rimmed sheet pan.

Position a rack 8 to 10 inches from the broiler and turn the oven to broil o n high. Broil the turkey for 8 to 10 minutes turning halfway though. Or until the skin is brown and crisp. Let the turkey rest 10 to 15 minutes before carving.

Remove the carrots and onions and smash up the garlic pieces. Pour the drippings a glass measuring cup, then allow the drippings to cool a bit so that the fat rises to the top and starts to solidify. Use a spoon to remove the fat. If you don't have enough drippings to equal 2 cups, add enough chicken or turkey stock until you have 2 cups of drippings.

Pour your two cups of stock/ drippings into a small saucepan. Cook on medium-high heat until it bubbles. Reduce by 25%.

In a small bowl mix together a ¼ cup of the warm stock and the cornstarch. Stir until smooth and dissolved.

Reduce the heat to a simmer. Whisk potato starch mixture into the pan, continue to whisk for about 30 seconds to 1 minute until thickened. Add salt and pepper to taste. If you have any lumps pour the gravy through a fine mesh strainer and into your gravy pitcher.