Bánh phồng tôm (prawn crackers)

Step 1: Blend 9 oz raw prawns and 2 garlic cloves to a smooth paste in a food processor.

Step 2: Mix 9 oz tapioca starch, 1 tbsp sugar, 1 tsp salt and ½ tsp ground white pepper in a bowl, add the prawn paste and knead, adding ¼ cup water a spoonful at a time, until you have a smooth, soft dough that does not stick to your hands.

Step 3: Divide into 3 and roll into logs about 4 cm thick. Wrap each tightly in baking paper or cling film suitable for steaming.

Step 4: Steam over high heat for 40 minutes, until the logs are firm and translucent all through and the prawn inside is fully cooked; a skewer should come out clean with no white starch.

Step 5: Cool, then chill the logs overnight until firm enough to slice cleanly.

Step 6: Slice the logs as thin as possible, about 1–2 mm. Spread in one layer on racks and dry in the sun for 1–2 days or in a 50–140°F oven for 4–5 hours, until hard, brittle and see-through. Common mistake: frying before they are bone dry; damp crackers stay dense and chewy. Dried crackers keep for 2 months in an airtight jar.

Step 7: Heat 1 litre neutral oil in a wok to 350°F over medium-high heat. Fry a few crackers at a time for 5–10 seconds, until they puff up and turn white or pale pink, then lift out with a slotted spoon onto paper towels.