Prep the Coffee Bean Turkey

1. Brine the turkey overnight
2. Preheat the oven to 350 degrees F
3. If the turkey has a metal clamp on its legs, remove it. Remove the giblets and neck from the cavity, if included, and discard. Remove the cavity fat, then rinse the turkey well and pat dry with paper towels.
4. In a small bowl, mash 6 tablespoons room-temperature butter until smooth and season with salt and pepper. Using your fingers, and starting from the cavity end of the turkey, separate the skin from the breast meat, being careful not to tear the skin. Gently rub the softened butter evenly over the breast meat, then insert 6 of the sage leaves under the skin, placing 3 leaves on each breast half. Pat the skin back into place, and then brush the whole exterior of the bird with some of the melted butter. Season the turkey all over, including the cavity, with salt and pepper. Sprinkle the coffee beans inside the cavity.

Roast the Coffee Bean Turkey

1. Brush the bottom of a roasting pan just large enough to accommodate the turkey with the bacon fat, then make a bed of the onion slices in the center of the pan. Place the turkey, breast side up, on top of the onion slices.
2. Place the turkey in the oven and roast for 1 hour. Baste the turkey with some of the melted butter and add the garlic, the remaining sage leaves, and 5 cups of the broth to the pan. Continue to roast the turkey, basting with butter at regular intervals a few more times, for another 1 1/2 to 2 hours. If the turkey is browning too much, tent with aluminum foil. The turkey is done with a thigh joint is pierced and the juices run clear, or when an instant-read thermometer inserted into the thickest part of a thigh away from the bone registers 155-165 degrees F. Save the juices from the turkey in the roasting pan.
3. Remove the turkey from the oven, transfer to a platter, and tent with aluminum foil. Let rest for about 20 minutes.

Make the Sweet Onion Gravy

1. Before beginning, remove any stray coffee beans that may have escaped from the turkey cavity into the roasting pan. Set the roasting pan with the onion slices and juices on the stove top over medium-high heat. You may need to straddle the pan over two burners. Using a wooden spoon, stir up any browned bits stuck to the pan and continue stirring for a few minutes. Sprinkle the flour evenly over the onion and juices and stir until well combined, about 1-2 minutes. Add 2 cups of broth, 1/4 cup white wine, and any juices that have collected around the turkey on the platter, then simmer gently, whisking occasionally, until thickened, 8-10 minutes. If the gravy seems too thick, add more broth. Season with salt and pepper, to taste. Pour gravy into a warmed gravy boat and keep warm.
2. Carve the coffee bean turkey and serve with the gravy immediately.