Add the smoked paprika, mustard powder, mustard powder, onion powder, garlic powder, salt and pepper, mix well.

Add the chicken breasts to a roasting pan and rub well with the spice blend until they are all completely covered.

Cover and refrigerate 1 hour to overnight.

1 hour prior to roasting, remove the chicken from the refrigerator and allow to come to room temperature while preheating oven to 300 °F/150°C.

Mix the chicken stock with 1/4 cup (60 ml) of barbecue sauce and pour the bottom of the baking dish. Add the chicken breasts, coating with the sauce and cover tightly with foil.

Roast for 1 hour, then remove the foil. Turn over the chicken breasts and continue to roast for 30 minutes more.

After removing from the oven, remove the chicken from the pan. Pour some of the liquid out of the pan and reserve about 1 cup (236 ml) in the roasting pan. Stir in 1 cup of the barbecue sauce, then add the chicken back into the pan.

Using 2 forks, going with the grain, shred the chicken mixing with the sauce as you go.

Serve warm on toasted buns and extra sauce.