Pierce the steaks with a fork to make numerous holes.
In a medium bowl, mix BBQ sauce, scallions, garlic, rosemary, and jalapeno pepper. Remove 1/2 cup of mixture and reserve for rolls. Add 1/4 cup oil and the steaks to the bowl and let marinate for 30 minutes, or up to 2 hours.
Preheat grill to medium and oil grates.
Place steaks on the oiled grill and grill 3 to 4 minutes on each side. Remove steaks to a plate and set aside.
Rub grill with 2 tablespoons oil. Grill onions until desired char marks are made. Brush the cut sides of the rolls with melted butter and toast (or grill); set aside. Top each steak with 2 slices of cheese and some grilled onions. Place the steaks back on the grill, and cover until cheese is melted. Spread toasted buns with the 1/2 cup of reserved sauce, if desired, and place the steaks on the bottom half of the rolls. Cover with the top halves and serve with coleslaw and pickles.
Recipe courtesy of Aaron McCargo Jr., 2009