Rub the pork belly with ½ tsp salt and ½ tsp sugar all around. Cover and leave to stand in the refrigerator for about 2 hours. Then preheat the oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer).
Place the belly with the fat facing upwards in an ovenproof dish and cook in the oven for about 1 hour. Then lower the oven temperature to 120 °C (electric cooker/circulating air: 100 °C/gas: see manufacturer) and cook for another hour.
Remove and allow to cool slightly. Wrap tightly in foil and leave to cool in the refrigerator for 2-3 hours.
Cut cold pork belly into thin slices. Rinse shrimps and pat dry. Season with salt and pepper. Heat the oil in a wok or large frying pan. Fry the prawns for 2-3 minutes.
Season with salt and pepper. Leave to cool. Sort the sprouts, wash and spin dry well.
For the crêpes, mix rice flour with approx. 1 teaspoon of salt and turmeric. Using a whisk, first stir in coconut milk, then mineral water. Pour through a fine sieve. Clean and wash spring onions and cut into thin rings.
Stir the spring onions into the dough. Put the dough in a cool place for about 1 hour.
For the dip, cut the chilli lengthwise and cut into rings with the seeds. Heat the fish sauce slightly in a pot and dissolve the sugar in it. Let it cool down. Stir in lime juice and chilli.
In a coated frying pan with lid (approx. 28 cm Ø), heat ½ TL oil over medium heat. Put 1 ladle of dough into the pan and swing the pan back and forth so that the dough is spread on the bottom of the pan.
Cover the dough with 4-5 prawns and 5-6 pork belly slices and spread 1 handful of sprouts on one half.
Put the lid on the pan and let it stand for 3-4 minutes. As soon as the underside has golden brown spots, fold the crêpe half over the other half without the sprouts. Lift the finished crêpe onto a plate or keep warm.
Bake 3-4 more filled crêpes from the remaining ingredients. Wash the herbs, shake dry, pluck off the leaves and sprinkle over the crêpes. Add the dip.