One of the most famous Vietnamese appetisers, but be prepared for a lot of work (preferably done with a food processor and an army of helpers).
Ingredients
1 whole onion
1 taro root (can be replaced by 3 shredded carrots)
1 garlic clove
1 shallot, or 3 scallions (scallions is better, but harder to find)
500g filling (either minced pork, crab or shrimp–I use ⅔ pork, ⅓ shrimp)
6 nam meo, or wood ear mushrooms
70-80 g of bean thread vermicelli
2 eggs
2 teaspoons sugar
1 pinch of salt and 1 pinch of pepper
2 tablespoons of fish sauce
Rice papers, 30-40
Instructions
Making the filling
Soak the bean thread vermicelli in warm water for 30 min. In a separate bowl, soak the mushrooms for 30 min.
Peel and cut the taro root into small pieces. Slice the following ingredients into small pieces: shallots, the garlic clove, the crab/shrimp if using any, the nam meo (cut the stems off and discard, slice the rest), and the vermicelli (cut length-wise into knuckle-length pieces).
Mix everything you've just cut up. Add the eggs, sugar, salt, pepper and fish sauce, and mix until you have an sort-of-even filling.
Making the rolls
Set up a rolling station, which consists of a large flat area of the kitchen, and a large dish to receive the rolls. Take a large bowl, fill it with 2L of warm water, and dissolve 3 tablespoons sugar into it.
Take a rice paper, put it in the water, wait until it starts to yield under your fingers, and put it flat on your rolling surface. Put 1-2 tablespoons of the filling on the middle, fold the side towards the middle, the front of the rice paper towards the middle (into a sort of enveloppe shape), and roll into a small cylinder. Set it aside, and continue until you run out of rolls (or fillings).
Frying the rolls
Deep-fry the rolls at 180°C for 15 minutes, or until golden. Drain on kitchen paper.
Serve with salad and nuoc mam dipping sauce.
Recipe by Aliette de Bodard at https://www.aliettedebodard.com/recipes/cha-gio-fried-rolls/