Preheat your grill to medium, about 350-400°F.
Pat the turkey dry and remove giblets and the neck.
12-20 pound whole turkey
Stuff the cavity with half of the onion and lemon quarters and herbs. Tie the legs together with twine.
1 yellow onion, 1 lemon, 1 bunch fresh herbs
Place the turkey in a double stack aluminum pan (two pans stacked on top of each other creates a sturdier vessel for your turkey).
Brush the melted butter all over the turkey. Sprinkle the turkey generously with salt and pepper all over the skin.
½ cup unsalted butter, Kosher salt and freshly ground black pepper
Scatter the remaining onion and lemon quarters around the turkey. Pour the chicken stock in the pan. Do not pour it on top of the seasoned turkey.
1 cup low-sodium chicken broth
Place the pan on the grill. Close the lid and cook, monitoring the temperature, for 2⅓-3 hours, or until the turkey registers 180°F in the thickest part of the thigh. Check the turkey every 30 minutes. Baste with the juices in the pan. Let rest for at least 30 minutes before slicing and serving.