Peel and slice the potato into 2 cm cubes.
In a separate bowl, mix the orange rind, orange juice, ginger, salt and malt to make the glaze.
Place the sweet potato in a baking dish.
Pour the glaze over the sweet potato and arrange the onion around the sides.
Bake for 30 minutes turning occasionally.
Note: Barley malt is available from health food aisles of the supermarket or health food stores. It looks like a dark syrup.