Take a large, deep saucepan or deep-fat fryer and fill with 1 litre oil. Heat until it reaches 175℃ (350℉).
In a medium bowl, use chopsticks to whisk the dry ingredients and seasonings (50 g cake flour, ⅛ teaspoon red chilli powder, ¼ teaspoon garlic salt, and ¼ teaspoon sugar) together, then gently stir in 1 egg yolk, 3 ice cubes, and 50 ml cold water.
Coat the seaweed in the batter by gently dipping both sides in the batter. Carefully drop into the oil. Repeat with a few pieces of nori, being careful not to overcrowd the pan.
Fry until golden and crispy, which may take 1-2 minutes.
Drain the seaweed crisps using a large frying spoon, and serve immediately.
Notes
Optionally, you can also double-coat the seaweed for extra crispiness. By this, I mean dip the seaweed in batter once, fry, and then once cooked, dip in the batter and fry once more. If you like a thicker coat of batter, this is the best way to achieve it — of course, you’ll need half the amount of seaweed mentioned in the recipe.