- Soak mung beans in hot water for at least 1½ hours or overnight.
- Drain soaked mung beans and transfer into a blender then add coconut milk and 1 cup of sparkling mineral water and puree until mung beans are very smooth.
- Transfer mung bean puree into a large bowl and then add rice flour, potato starch, cornflour, turmeric powder, salt and remaining sparkling mineral water. Mix all ingredients together until smooth and allow the batter to rest for at least 45 mins (or overnight in the fridge).
- Add garlic, chilli, sugar and 2 tsp of salt into a mortar to make the dipping sauce. Use pestle to crush garlic and chilli until smooth.
- Transfer to a bowl, add hot water and mix all ingredients until sugar and salt dissolve.
- Add vinegar and lime juice, then season to taste. Set aside.
- Take batter out from the fridge and allow to come to room temperature. Add sliced spring onions into the bowl and gently stir all batter until mixed through.
- Add 1½ tbsp of vegetable oil into a wok. Add mushrooms in the wok and cook for a few mins, then transfer to a large bowl.
- Add fried tofu and tempeh into the bowl. Add soy sauce, sesame oil and black pepper to taste.
- Add 1½ tbsp of vegetable oil into a cast iron pan, then heat on medium low.
- Using a large ladle, pour in enough of the batter into the pan to cover the surface.
- Swirl the batter until it covers all of the pan’s surface in a thin layer.
- Reduce the heat to low and cook the pancake for 3-4 mins until the edges begin to crisp and pulls away from the pan.
- Add half a handful of beansprouts onto the pancake, then cover the pan with the lid for about 40 secs.
- Open the lid and allow some water to evaporate and then add tofu and tempeh and then fold the crepe in half and put it onto a serving plate.
- Serve the crepe with lettuce, Vietnamese herbs and dipping sauce, and garnish with coriander and sliced chillies.