Quarter the orange and remove the peel from the flesh of the fruit. You will only need one or two of the quarters of the peel. You will not need the fruit itself.
Using a sharp knife, very carefully remove the white part (this pith) from the orange part of the peel. Remove as much as possible to remove bitterness from the peel.
Bring a small pot of water to a boil. I use the same pot that I used for the panna cotta. Drop the peel into the pot. Boil one minute. Pour the contents of the pot through a strainer (pour out the water in the pot). Rinse the peel under cold water.
Repeat the previous step two more times. In total, you will boil the peel three times. This removes the bitterness from the peel.
Rinse out your pot. Combine the water and the sugar in the pot. Bring to a boil.
While the sugar syrup is coming to a boil, use a sharp knife to thinly slice the peels. The thinner the better.
Once the sugar syrup has reached a boil, drop the slices of orange peel into the syrup. Lower the heat and simmer for 45 minutes. Keep an eye on the pot to ensure your syrup doesn't boil away and you don't burn the peels.
While the peels are simmering, get ready to coat the peels in granulated sugar. Fill a small dish with granulated sugar, deep enough to toss the peels in. Also, set a cooling rack over a sheet tray.
One the peels are done poaching, remove the peels from the syrup. Quickly toss them in the granulated sugar. Then place the candied peels, separated from one another, on a the cooling rack. Let harden overnight.