Method

• 1.
  For chips, bring a large pan of salted water to the boil. Add potatoes and cook for 5 minutes or until just cooked. Drain and pat dry with paper towel. Place on a wire rack in freezer for 20 minutes to dry out.
• 2.
  Half-fill a deep-fryer or large saucepan with oil and heat to 150°C (a cube of bread will turn golden in 1 minute 20 seconds when oil is hot enough). In batches, deep-fry potatoes, turning halfway, for 5 minutes or until light golden. Remove with a slotted spoon and pat dry with paper towel. Return to wire rack and freeze for a further 15 minutes or until cooled.
• 3.
  Meanwhile, discard any mussels that do not close when tapped sharply. To cook mussels, melt butter in a saucepan over high heat. Add eschalot and celery, and cook, stirring occasionally, for 5 minutes or until soft. Add mustard and cider, and bring to the boil. Add mussels, then cover and cook, shaking pan occasionally, for 3 minutes or until mussels start to open.
• 4.
  To finish chips, increase oil temperature to 190° (a cube of bread will turn golden in 30 seconds when the oil is hot enough). In batches, cook chips for 3 minutes or until golden and crisp. Remove with a slotted spoon and drain on paper towel. Season with salt and lemon myrtle, if using.
• 5.
  Toss mussels with dill, then top with apple and drizzle with oil. Serve with chips and lemon cheeks.