Confit duck is one of the most rewarding things you can make. This is my full method.
Green salt (from Thomas Keller’s French Laundry): blitz 4 tbsp salt with 1 tbsp picked thyme, 1 tbsp parsley leaves, 3 chopped bay leaves and 1 tbsp coarsely ground pepper. It keeps for a week or two. At Christmas I add orange and lemon zest and use it on turkey legs.
Salt the legs: coat them generously all over, lay them skin side down, loosely cover and leave for 6 hours. Rinse and pat dry. You can hold them in the fridge overnight at this point.
Confit: submerge them in duck fat and cook low and slow at 120°C fan until meltingly tender. Stored in their fat, they keep for ages, ready to crisp up whenever you like.