Slice chicken breasts into 1 x 1 inch cubes. In a mixing bowl, add the chicken, sliced red onion and Dad's All Purpose Rub. Mix it all together and set aside.
Preheat the griddle to a medium high heat.
Place the seasoned chicken on the flat top and continuously flip to get an even cook throughout. Next, add in your choice of BBQ sauce and continue mixing.
Once the chicken reaches an internal temp of 150 degrees, place slices of pepper jack cheese over the entire pile. Place a lid over the top to allow the cheese to melt.
Toast up some mini french rolls and scoop up a generous serving of the BBQ chicken mixture into the roll.