Preheat the oven to 500 degrees. In a roasting pan, toss the butter, garlic, butternut squash, apples, and onions together. Sprinkle with salt and pepper.

Mix together the butter, thyme, rosemary, orange and lemon zest, and garlic in a bowl. Place about 1/4 cup of salt and 2 teaspoons pepper in two small bowls. Get a piece of kitchen twine ready to tie the legs together. Place all of this near the roasting pan so you won't need to get turkey juices everywhere when you're prepping.

Remove the turkey from the bag and pull out anything in the cavity. Place the turkey on top of the vegetables and pat it dry. Cut a small slit in the skin above the cavity and gently work your hand between the skin and the breast meat. Spread the butter mixture under the skin, then rub it all over the breast, legs, thighs, and cavity of the bird. Sprinkle with Kosher salt. You probably won't need the entire 1/4 cup, but it should look like a light snow has fallen on the turkey. Follow that up with a sprinkling of pepper.

Place the orange halves in the cavity along with a few apple and onion slices from the pan. Tie the legs together with kitchen twine and tuck the wing tips under the bird to protect them.

Place the turkey in the oven uncovered for 30 minutes, or until it is golden brown. Remove the turkey from the oven and lower the temperature to 350 degrees. Pour the chicken broth, hard cider, and apple cider into the pan, scraping up any bits at the bottom. Cover the breast meat with a small strip of parchment paper. Wrap the pan in foil. Place an oven safe or probe thermometer in the breast meat then return to the oven and continue to roast for 2-2 1/2 hours or until turkey reaches about 150 degrees. At that point, remove the foil and continue to roast until the turkey reaches 161 degrees. Remove the turkey from the oven, tent with foil, and let rest for about 30 minutes before carving.

To make the gravy, strain the vegetables, reserving them and the liquid for another use. Skim the fat off the top of the liquid. You can use a gravy separator or place it in the fridge for a bit to make it easier.

Place a 1/4 cup of the fat from the pan in a pot over medium heat. If you weren't able to get a full 1/4 cup of fat, add enough butter to make a 1/4 cup. Measure out a 1/2 cup of the liquid from the roasting pan and whisk it together with the cornstarch to form a slurry. Stir this into the fat in the pan, whisking until the mixture begins to thicken. Slowly stir in the broth and then the cider in a steady stream, alternating stirring and whisking. Continue to cook for another 5 or so minutes, or until the gravy is the consistency you want. If desired, whisk in mustard then season to taste with salt and pepper. Serve the gravy with the turkey.