Using a vegetable peeler, peel the rind from the limes trying to leave all the white pith behind. Juice the limes to get 1/3 cup juice.
Combine cranberry juice, sugar, sauce, lime juice and cinnamon stick in a saucepan. Stir until sugar dissolves. Simmer for 5 minutes. Add rhubarb and simmer over medium heat for 20 minutes or until mixture is bright red and syrupy.
Strain well (you’ll need 1 cup of syrup for the glaze). Add lime rind and mustard and whisk to combine. Set rhubarb pulp aside to serve with the carved ham.
Preheat oven to 180°C. Carefully remove rind from ham, leaving as much fat as possible on the joint. Using a sharp knife, score a diamond pattern into the fat, taking care that you don’t cut all the way through to the meat. Place ham on a rack in a roasting dish and pour 2cm of water into the base of the pan.
Brush syrup over ham to coat well. Bake ham for 1 hour, re-brushing with rhubarb glaze every 15 minutes, until glossy. Serve ham with rhubarb pulp and any remaining glaze. Serving suggestion: Add the cranberries to the rhubarb glaze in the last 15 minutes of cooking. Remove from the oven and allow to cool slightly. Spoon the cranberries over the top of ham so they sit on top as a lovely decoration.