Prepare the prawns. Sever the head and remove the intestines. Leave your tail on your body. Rinse the prawns, pat dry and marinate in the refrigerator for approx. 20 minutes with the soy sauce and pepper. In the meantime, pluck the leaves off the coriander and chop the stalks. Crush the coriander root, the coriander stalks, garlic and chili peppers in a mortar and grate. Mix the lime juice, palm sugar and fish sauce in a bowl. Add the ground paste and mix everything well. Heat the oil in a wok or pan over medium temperature. Fry the prawns without the marinade for about 3 minutes until they are red. Arrange the prawns on a preheated platter, drizzle with part of the vinaigrette and serve sprinkled with the coriander leaves. Serve the rest of the vinaigrette separately for everyone at the table to regulate the sharpness and aroma.