The day before making this recipe, take the chicken out of its packaging, and leave uncovered in the fridge overnight, drying out the skin which results in a crispy bird when cooking.
On the day of, fill the chicken cavity with the two lemons and onions (sliced in half). Spread the olive oil all over the outside of the bird, and sprinkle half the rub seasoning over it.
Mix the other half of the rub with the melted stick of butter.
Get a hot burning fire built on both sides of the spit, but not directly under it (the key to this recipe is using a rotisserie / spit to roast your chicken, but an indirect grilling setup or oven works at well)
Let the chicken roast, basting it with the butter mixture every 20 minutes or so. When the chicken reads 165F internal temperature on the breast, take it off the spit and let rest
After resting the chicken for 10 minutes, carve it up serve.