Mix the dry rub ingredients together in a medium size bowl (Salt, Pepper, Garlic Powder) and sprinkle it all over the bottom round. Allow this to sit in the refrigerator for about 30 minutes or overnight. The longer the better.

Grill the bottom round on a smoker with direct heat at 300 degrees F until the internal temperature reaches 135 degrees F. You can use a standard grill by searing the outside, and then moving the bottom round to indirect heat until it reaches a medium rare (the same 135 degrees F internal temp)

Wrap the cooked meat in aluminum foil and allow to rest for 30 minutes.

Using an electric knife or on a meat slicer, slice the meat thinly.

Using an electric knife or the meat slicer shave slices of the onion.

To serve place the thinly sliced beef on the rolls with the shave onions, with the appropriate amount of horseradish sauce and enjoy!