01 - Wash the oranges thoroughly under running water. Using a sharp knife, score each peel from top to bottom into quarters. Gently remove the peel in sections, keeping a thin layer of white pith intact for texture.
02 - Slice the peels lengthwise into uniform strips approximately 1/4 inch wide for even candying.
03 - Place the strips in a saucepan, cover with cold water, and bring to a rolling boil. Boil for 2 minutes, then drain completely. Repeat this blanching process two more times to draw out excess bitterness from the pith.
04 - In the same saucepan, combine the granulated sugar and water. Bring to a gentle simmer over medium heat, stirring constantly until the sugar fully dissolves and the liquid runs clear.
05 - Add the blanched peels to the simmering syrup. Maintain a gentle simmer for 40 minutes, stirring occasionally to prevent sticking, until the peels turn translucent and absorb the syrup evenly.
06 - Using tongs, carefully transfer each strip to a wire rack set over a sheet of parchment paper. Allow the peels to dry undisturbed for at least 1 hour until tacky but no longer wet.
07 - Break the dark chocolate into pieces and melt in a heatproof bowl set over a pot of barely simmering water, stirring gently until smooth. Alternatively, melt in the microwave in 20-second bursts, stirring between each interval.
08 - Dip each candied peel strip halfway into the melted chocolate, allowing the excess to drip back into the bowl. Place each coated strip onto a fresh sheet of parchment paper.
09 - Sprinkle lightly with flaky sea salt if desired. Let the chocolate set at room temperature for about 30 minutes until fully hardened and glossy.