Vietnamese vegetable spring rolls with plum sauce

Cut the leaves from the pak choi and slice the stems into matchstick strips. Heat 1 tablespoon of the oil in a wok or large frying pan, add the sweet potato and carrot and stir-fry for 2 minutes. Add the spring onions and pak choi stems and cook for 1 minute. Mix in the bean sprouts, garlic and ginger and cook for 1 minute. Transfer to a bowl.

Heat the remaining oil in the pan, add the pak choi leaves and cook for 2–3 minutes until just wilted.

Dip a rice pancake into a bowl of hot water and leave for 20–30 seconds until softened. Lift out and place on a clean tea towel. Top with a pak choi leaf, one-eighth of the vegetable mixture and 2 stems of coriander. Fold in the pancake edges and roll up tightly. Repeat with the remaining pancakes to make 8 spring rolls. Cover with clingfilm and set aside. Serve within 1 hour.

Meanwhile, make the sauce. Put the plums in a small saucepan with the measurement water, cover and cook for 5 minutes until softened. Purée the plums with the soy sauce in a food processor, then mix in the sugar and wasabi to taste.

Garnish the spring rolls with the remaining sprigs of coriander and serve 2 per person with small bowls of the sauce.