1Peel onion. Cut a small piece off of bottom so it will sit straight. With a sharp knife cut onion almost in half vertically, leaving one inch uncut at bottom of onion. Repeat until you have eight cuts
2Pry onion sections open a little, being careful not to break completely.
3Pour the BBQ sauce into the cuts. Add bacon bits and cilantro, pushing into cuts of onion as you did the BBQ sauce.Place the butter on top of the onion
4Wrap the onion in foil and grill 30-45 minutes, depending on the size of the onion.