Prepare the turkey:

1. If frozen, thaw the turkey 24 hours per 4-5 pounds.
2. Remove from the package and drain, then remove the neck and giblets (save or toss these, up to you).
3. Place the turkey on a cutting board or in a large pan and rub 1/4 cup of the butter underneath the skin of the breasts.
4. In a small bowl, combine a rub of salt and freshly cracked pepper. 1 part salt to 2 parts pepper (roughly 4 tsp salt and 8 tsp pepper per 5 lbs of turkey).
5. Rub the salt and pepper generously all over the turkey.

On the grill:

1. Charcoal: Set about 20-30 charcoal briquettes in a tall pile on the grill, near the grate. Keep the grate open slightly, about 25%, and open more or less throughout cooking in order to keep the grill at a steady 250-275°F.
2. Light about 10 briquettes or place them in a starter and add them to the existing coals. Place your turkey once the coals have ashed over.
3. Smoker: preheat the smoker to 250°F and add pellets as needed (about 1 pound per hour of cooking).
4. Place the turkey on the side of the grill opposite the heat source, breast side up. *If your grill has a second rack, make sure it is removed or adjusted so it wont touch the turkey.
5. For a 15 pound turkey, cook around 2 hours 45 minutes. (Around 15 minutes per pound)
6. Wrap the turkey tightly in two layers of heavy duty aluminum foil and top it with the remaining 3/4 cup butter before closing (the turkey will braise in the butter and its own juices).
7. Cook 1 more hour, or until a thermometer inserted into the center of the breast, legs and wings read 160°F.
8. Remove the turkey and rest about 30 minutes before carving.
9. Serve on a bed of greens.