Preheat oven to 180°C.
Remove the rind from the ham leg and reserve for storage.
Score the fat in a diamond pattern and press star anise into the diamonds.
Place ham on a rack in a roasting tray with a small amount of water in the base.
Heat glaze ingredients in a saucepan over low heat until sugar dissolves.
Pour glaze over the ham to cover all exposed fat.
Bake for 30-40 minutes, basting occasionally, until golden.
Transfer ham to a large platter for carving.
Boil sliced potatoes in salted water for 8-10 minutes until just tender.
Whisk olive oil, lemon juice, sumac, salt, and pepper in a bowl.
Toss hot potatoes with half the dressing, cool, then mix with remaining vegetables, herbs, and dressing.
Serve ham slices with a spoonful of potato salad.