Potato gratin with Shanagarry smoked salmon

900g even-sized ‘old’ potatoes (Golden Wonders or Kerrs Pinks)

salt 

pepper

275ml milk

275ml double cream

small garlic clove, peeled and crushed

nutmeg

110-170g Irish smoked salmon

1 tbsp parsley, chopped

1 tbsp chives, chopped

4 small ovenproof gratin dishes: 11.5cm bottom and 15cm top