01 - Wash the oranges thoroughly under running water. Using a sharp knife, score each peel from top to bottom into quarters. Gently remove the peels in sections, keeping as much of the white pith attached as possible. Slice the peels into uniform strips approximately ¼ inch wide.
02 - Place the peel strips in a saucepan and cover with cold water. Bring to a rolling boil and cook for 2 minutes, then drain completely. Repeat this blanching process two more times to draw out excess bitterness from the pith.
03 - In the same saucepan, combine the granulated sugar and water. Bring to a simmer over medium heat, stirring constantly until the sugar has fully dissolved and the liquid is clear.
04 - Add the blanched peel strips to the sugar syrup. Reduce the heat to maintain a gentle simmer and cook for 40 minutes, stirring occasionally, until the peels become translucent and the syrup thickens noticeably.
05 - Using tongs, carefully transfer each candied peel strip to a wire rack set over a sheet of parchment paper. Arrange in a single layer and allow to dry at room temperature for at least 1 hour, or until the surface is no longer sticky.
06 - Break the dark chocolate into small pieces and place in a heatproof bowl. Set the bowl over a saucepan of gently simmering water, stirring until completely melted and smooth. Alternatively, melt in the microwave in 20-second intervals, stirring between each burst.
07 - Dip each candied peel strip halfway into the melted chocolate, allowing any excess to drip back into the bowl. Place each dipped piece onto fresh parchment paper. Sprinkle lightly with flaky sea salt if desired. Allow the chocolate to set completely at room temperature, approximately 30 minutes.