Preheat outdoor smoker to approximately 225 degrees F.
Remove silver skin from ribs, or have butcher do it for you. Brush with mustard then very generously season with salt and pepper, on both sides. Place in a smoker and cook until internal temperature reaches about 155 degrees F, about 1 1/2 to 2 hours. Serve with BBQ sauce on the side, if desired.
Smokey Mountain BBQ Sauce:
In a small saucepan, combine all ingredients and bring to a simmer for a few minutes for flavors to combine.