Dry turkey breast and move to rack. Coat breast evenly all over with butter. Season roast all over with salt and pepper. Boneless breasts come dressed in a string bag. Leave it in place until after cooking.

Roast breast 90 minutes. Test internal temperature and keep roasting until the interior temperature reaches 165°F on an instant read thermometer. Allow breast to rest 10 minutes before carving. Gently snip the string bag open to carefully remove it, leaving as much skin in place as possible. Slice as desired.

While the breast is roasting, melt butter in a small saucepan over medium heat. Sauté garlic in the hot butter 30 seconds. Whisk in flour and cook until starting to turn light brown and all the white flour is incorporated. Zest and juice a medium orange and pour the juice slowly into the flour, stirring constantly. Whisk in brown sugar, bourbon, and stock, and stir until thickened. Stir zest into remaining gravy and keep warm. If gravy is too thick, adjust with additional stock.

If drippings have collected, add to any gravy made for serving.