Nem ran (Hanoi fried spring rolls)

Step 1: Soak 1 oz glass noodles (mung bean vermicelli) and ⅓ oz dried wood ear mushrooms in separate bowls of warm water for 10 minutes until soft. Drain, squeeze dry, cut the noodles into 3 cm lengths and finely chop the mushrooms.

Step 2: In a large bowl mix 10 ½ oz pork mince, 4 oz cooked crab meat or raw peeled prawns, 1 carrot, 2 shallots, 2 spring onions, 1 egg, 1 tbsp fish sauce, ½ tsp ground black pepper and ½ tsp sugar with the noodles and mushrooms. Squeeze out any liquid from the carrot first so the filling is fairly dry.

Step 3: Stir 1 tbsp rice vinegar into 1 cup water in a wide shallow dish. The vinegar helps the rice paper brown and blister.

Step 4: Dip a sheet of 20 rice paper sheets in the water for 1–2 seconds and lay it on a board; it softens as it sits. Put a heaped tablespoon of filling along the lower third in a 6 cm log.

Step 5: Fold the bottom over the filling, fold in the sides and roll up snugly but not tight. Common mistake: rolling too tight or overfilling makes the wrappers split as the filling swells in the oil.

Step 6: Repeat with the rest and leave the rolls on a tray, not touching, for 10 minutes so the wrappers dry a little. You can freeze them uncooked at this point and fry from frozen, adding 3–4 minutes.

Step 7: Heat 4 ¼ cups vegetable oil in a wok or deep pan to 325°F over a medium heat. Fry 6–7 rolls at a time for 8–10 minutes, turning, until pale golden and the filling reaches 160°F/160 °F in the centre of a roll.

Step 8: Lift them out onto a rack. When all are done, raise the heat so the oil reaches 350°F.

Step 9: Fry the rolls again in batches for 1–2 minutes until deep golden and crackly, then drain on kitchen paper.

Step 10: Snip each roll into 2–3 pieces and serve with 7 oz rice vermicelli, 1 lettuce and herbs (mint, perilla, coriander) and ¾ cup Vietnamese fish-sauce dip (nước chấm) for dunking.