Wash (5-6 medium) potatoes and remove any bad spots. Slice them into wedges the size of steak fries. cut onion in half then half again and slice.
Combine potatoes, onion, minced garlic, jalepeno rings, jalepeno juice, BBQ sauce and grill seasoning in baggie. Let marinade for 30-40 minutes
Tear a large (24x18) piece of heavy duty foil, spray with nonstick cooking spray, pour potato mixture onto foil and dollop butter all around potatoes, season to taste with salt and pepper.
fold foil packet leaving a small air space for steam. place on campfire over hot coals or in preheated bbq grill cooking for 30-40 minutes turning halfway through cooking time. these are done when fork tender.