Combine 1 cup of the cider, the mustard, ginger and cloves in a large frying pan. Bring to a simmer. Add the sweet potato. Cover tightly and simmer until partially tender, 15 minutes.
Add ham steak; cover with sweet potato slices. Arrange apple wedges over the top. Cover and simmer until apples and potato are tender and ham is heated through, 10 to 15 minutes.
Using a slotted spoon, transfer ham, potato and apple to plate. Cover with aluminium foil to keep warm.
Blend cornflour and 1 tbsp cider in a small bowl. Stir a little of the hot pan liquid into the mixture until smooth. Add cornflour mixture into pan. Cook over medium heat, stirring, until slightly thickened, about 1 minute.
Divide ham, sweet potato and apple between 4 plates. Spoon on sauce from the pan. Garnish with spring onions.
Adding fresh fruit to a meat dish is an easy way to include more vitamins and fibre. Sliced pears, halved kumquats, orange segments or pineapple chunks could be used in this recipe in place of the apple.