Combine the barbecue sauce, mustard, soup powder, cola and tomato paste until well mixed.

Place the roast in a crockpot and arrange the potatoes (if using) around the meat. Cover all with the sauce mixture. This can cook in the crockpot on the low setting from sunset until lunchtime the following day. As it is a very forgiving cut of meat, it enjoys the slow cook. However, if you’re a little more rushed, it may be cooked on high for 4 hours during the day, then turned down to low for another 6–8 hours.

Another option is to roast the meat in the oven overnight at 230°F/110°C, but if you’re including potatoes, more liquid (about 2 cups) will be needed, as it is a dryer heat than crockpot cooking. Also ensure that the roasting dish isn’t too large for the meat, otherwise the sauce will evaporate and cook out too quickly.