Combine the orange, fennel, garlic, salt, sugar and spices. Put the duck legs in a bowl and cover them with this mix and while rubbing it into the legs squeeze the orange juice out. Cover with plastic wrap and fridge for 12 hours.
After refrigeration, give the duck legs a wash to remove the salt and then pat dry. Put them with the orange, fennel and garlic into a baking dish and cover with the duck fat. Cook confit style in a low oven of 140c for approximately 4-5 hours or until the meat is falling off the bone.
Once cooked and cooled to handle, remove the duck legs from the fat and pick all the meat from the bones – discard the skin. Finely chop the meat along with the orange and its zest and place in a bowl.
Add the pistachios, thyme and brandy and fold through. At this stage you can also add a little duck fat back into the mix and mix well to combine.
Place in the fridge until ready to use.
To preserve for a longer period, place in sterile jars and cover the top with duck fat. Place the lid on the jar and keep in the fridge. This method will preserve the rillette.