Mix the soy sauce, toasted sesame seeds, and sesame oil in a bowl; set aside.
In a pie plate or flat bowl, soak the rice paper in warm water one piece at a time to rehydrate. Place each piece of rice paper on a flat surface. Place some of the grated carrot, basil, mint, prawns, and avocado in the centre. Fold in both sides and roll up. Repeat for the remaining rice papers and ingredients.
Cut the rolls in half and serve with the reserved sauce.
