Remove the roast from the refrigerator 40 minutes prior to cooking and allow it to come to room temperature.
Set up and preheat your smoker to 250°F.
If using an electric smoker, fill the water bowl half way and place wood chips in the tray.
Open the top vent and. For a pellet grill, fill the hopper with enough pellets for up to 2 hours and ignite the grill with the top open.
Close the doors and lids on both smokers and allow them to come to temperature.
In a mixing bowl, whisk together the pepper, garlic powder, onion powder, salt, and sugar.
Coat the beef with the mustard using a brush or your hands.
Place the spice rub on all side of the roast, pressing it into the mustard so it sticks.
Place the roast directly on the smoker rack.
Insert the probe thermometer in one end of the roast (if a thermometer is attached).
Smoke for 90 minutes to 1 hour and 45 minutes or until the internal temperature reads 130 to 135°F.
Remember to check the water, wood chips, or pellets and replenish as needed.
Remove the cooked round roast to a clean cutting board and tent with foil.
Allow the meat to rest for at least 15 minutes before slicing.
Slice the cooked bottom round roast as thinly as possible, similar to how a deli would slice it.
This results in tender portions that are not chewy.
Place the slices on a platter and serve with your favorite side dishes.