1/4 cup unsalted butter
1 3/4 pounds celery root (celeriac, peeled and cut into 1/2-inch dice)
2 medium tart apples, such as Fuji or Braeburn (peeled, cored and cut into 1/2-inch dice)
  Sea salt (to taste)
4 gratings of fresh nutmeg
1 star anise pod
1 cup apple cider
1/2 cup heavy (whipping) cream