Put the mushrooms in a bowl, cover with water and soak for 20 minutes, then drain
and thinly slice.
To make the batter
, combine rice flour, tapioca
flour and salt with 20 fluid ounces/ 600 ml cold water. Now whisk
until the flour dissolves and forms a smooth batter.
Heat a nonstick frying pan
over medium heat, then add 2 tablespoons oil. Fry the garlic and shallots until fragrant, then add the pork, mushrooms, fish sauce
, sugar, and pinch of salt and pepper.
for 4 minutes, then transfer to a bowl and set aside.
Brush a round tray with oil and place beside the stove. Heat a large nonstick frying pan over medium heat, and add enough oil to coat the base of the pan. Pour a small ladleful (2 to 3 tablespoons) batter into the pan, turning the pan in a circular motion to cover the base with a thin layer of batter.
Cover the pan with a lid and cook for 30 seconds.
Remove the lid and slide the thin noodle sheet onto your oiled tray. Scoop 1 tablespoon pork mixture onto the noodle sheet, fold 2 sides in, then fold over to form a roll.
Transfer to a plate. Repeat this process using the remaining batter and pork mixture, adding oil to the pan as necessary.
Top the rolls with pork terrine
, fresh herbs
, bean sprouts
, fried shallots
, and cucumber. Dress
with nuoc cham and serve with sliced chile