Method

• 1.
  Place potato in a colander and wash under cold running water. Transfer to a bowl of cold water and stand for 10 minutes to soak. Drain, then thoroughly pat dry with paper towel.
• 2.
  Half-fill a deep frypan or wok with sunflower oil and heat to 180°C (a cube of bread will turn golden in 90 seconds when the oil is hot enough). In 4 batches, deep-fry potato, turning halfway, for 1-2 minutes or until golden. Remove with a slotted spoon and drain on paper towel. Scatter with a pinch salt flakes while hot and set aside.
• 3.
  Preheat the oven to 160°C.
• 4.
  Melt half the butter and 1 tbs olive oil in a large heavy-based frypan over medium heat. Add snapper frames and cook, turning halfway, for 7 minutes or until golden. Increase heat to high and add orange juice and wine, scraping base of pan with a wooden spoon. Bring to the boil and cook for 3-5 minutes or until reduced by one-third. Strain through a fine sieve into a bowl, discarding solids. Return liquid to pan, add eschalot and orange zest, and bring to a simmer. Remove from heat, add 1 tbs olive oil and remaining 30g butter, and whisk until well combined. Set aside.
• 5.
  Pour the sauce (‘orange buerre blanc’) into a large baking tray and place the fish fillets on top. Drizzle with the remaining 1 tbs oil, season with salt flakes and bake for 7 minutes or until just cooked through.
• 6.
  Scatter with fennel, reserved fennel fronds, parsley, mint and potato string fries to serve.