Add warm water to a stock pot and add salt, stirring until salt has dissolved. Add onion, garlic, peppercorns and fresh rosemary and lemon.
Submerge turkey breast in brine, cover and refrigerate 2-6 hours.
Remove turkey from brine and drain well. Pat with paper towels until dry.
Place on a clean baking sheet and coat with olive oil, rubbing all over skin and in cavity.
Season with salt, pepper and garlic.
Prepare grill or smoker to 300° fire.
Place turkey breast over indirect heat and smoke 30 minutes.
Remove from grill and wrap in peach butcher paper, sealing up like a packet.
Put wrapped turkey back onto grill and continue to cook for one hour or until internal temperature reaches 165°.
Remove from grill and unwrap butcher paper.
Allow turkey breast to rest 10 minutes before slicing.
Carefully save the drippings for gravy.