Arrange an oven rack at the bottom third of the oven. Remove any upper racks.
Preheat oven to 425°F.
Remove giblets and neck from turkey and discard. Drain cavity well; pat dry with paper towels. It's important to get the skin dry so that the butter will stick to the turkey!
Place half of the onions in the roasting pan and the remaining onions in the cavity of the turkey.
Place turkey, breast side up, in a roasting pan.
Gently loosen and lift skin from turkey breast without totally detaching skin. (you can use rubber gloves here!) Rub 3 tablespoons garlic butter under the skin.
Tuck or tie ends of legs together with kitchen string.
Generously rub the entire turkey including the cavity with remaining garlic butter.
Pour chicken broth into the base of the roasting pan.
Wrap each leg with 2 slices of bacon.
Wrap each wing with 1 slice of bacon and then tuck the wingtips under the bird.
Set out a large piece of parchment paper and place 8 pieces of bacon side by side, leaving no space in between.
Fold every other strip of bacon up about halfway. Lay another strip of bacon down, perpendicular to the others. Fold the parallel strips back down, then fold up all the other strips. Lay another perpendicular strip down, and repeat until all the strips have been used.
Rotate the parchment 90 degrees so that you are looking at a diamond instead of a square.
Gently flip the parchment paper over so the bacon is on the top of the turkey with the tip of the diamond at the neck of the turkey.
Once you have everything in place, tuck the ends of the bacon weave in so that no bacon is overlapping. Trim if necessary.
Place roasting pan in oven for 40 minutes. The bacon should be dark and slightly crisp.
Reduce oven temperature to 325°F.
Roast for an additional 2-2.5 hours or until the turkey reaches an internal temperature of 165°F. Timing will adjust based on the size of your turkey. The general rule of thumb is 13-15 minutes for each pound of turkey. Basting and opening and shutting the oven will affect cooking time as well. Use tin foil to cover the turkey if the bacon starts to get too crispy. Baste the turkey every 20-30 minutes.
Remove the turkey from the oven and place it on a serving tray. Allow it to rest for 30 minutes before carving.
Use the drippings to make a gravy (check out my bacon gravy recipe! Link in the post!)