Remove the legs and breasts of the duck, trimming off any excess fat. Chop off the head and discard. Remove the skin from the neck and add to the fat, and put the neck with the meat. Add the heart and the gizzard, cut in half and washed, to the meat.
Now trim all the skin and fat off the carcass. Keep the bones to make a stock for another recipe. Put all the fat in a pan and cover with cold water. Bring to a gentle simmer to render. This usually takes about an hour – the water should be totally evaporated and the fat clear. Pour the fat through a fine conical sieve without pressing.
Liberally sprinkle the meat with the salt and refrigerate for 90 minutes. Wipe off all the salt and moisture with a cloth and put the meat into the warm fat with the sage and thyme. Bring to a very gentle simmer, cover with a greaseproof paper and cook until tender, about 2 hours. The slower and longer it cooks the better. Leave to cool in the fat, then refrigerate. It will keep for several weeks.
When you want to eat the duck confit, lift the meat out of the fat and place, skin-side down, in a non-stick pan over medium heat until crispy and golden. Turn over and put in a preheated oven (180ºC/gas 4) to finish warming through for 10-15 minutes. Serve with sauté potatoes. The heart and gizzard can be eaten too.
Sauté potatoes
Peel the potatoes when cool. Cut into 5mm slices and pan fry in the duck fat. Season and sprinkle with garlic and parsley.