Method

• 1.
  Preheat oven to 150°C. Grease 2 baking trays and line with baking paper.
• 2.
  For nori seasoning, combine all ingredients on one tray and toast for 20 minutes or until golden. Transfer to a food processor with 1 tbs salt flakes and whiz until finely chopped.
• 3.
  Increase oven to 180°C. Place potatoes on remaining tray and toss with oil. Roast for 1 hour 10 minutes, stirring halfway, or until golden. Toss with 1/4 cup (30g) nori mixture.

• 4.
  Meanwhile, to make miso dressing, combine miso, eschalot and vinegar in a bowl and stand for 10 minutes. Gradually whisk in oil until well combined, then whisk in 1/4 cup (60ml) water. Transfer 1/4 cup (60g) dressing to a separate bowl and brush over lamb (reserve remaining dressing to serve).
• 5.
  Heat a chargrill pan or barbecue to medium-high heat. Cook lamb, continuing to brush with dressing, for 2-3 minutes each side for medium-rare, or until cooked to your liking.
• 6.
  Place potatoes and lamb on a platter and drizzle with reserved dressing. Scatter with watercress and sprinkle with remaining nori seasoning to serve.