1. Soak 180 gms (6.3 oz) dried rice vermicelli noodles in just boiled water for 2 minutes or until tender. drain and divide among serving bowls.
2. For the marinade, use a mortar and pestle to pound 1/3 cup sliced spring onion / scallions and 3 garlic cloves to a rough paste.
3. Stir through the remaining ingredients namely 1/4 cup fish sauce, 1 tbsp turmeric powder, 1 tsp curry powder, 1 tsp sugar, 2 tbsp vegetable oil and 2 tbsp finely chopped dill leaves. pour the marinade into a large bowl.
4. Add 800 gms fish fillets sliced into 4 cm wide strips and toss to coat.
5. To make nuoc cham dressing, in a small bowl add 2 cloves finely chopped garlic, 1 finely chopped red chilli, 3 tbsp white sugar, 3 tbsp fish sauce, 2 tbsp white vinegar, 2 tbsp lime juice.
6. Heat the vegetable oil in a large non-stick frying pan over medium-high heat.
7. Add the marinated fish, spreading the pieces out in the pan. allow to cook on the first side until golden for about 2-3 minutes. then gently turn the fish over, sprinkle over 2 tbsp water.
8. Cover with a lid and cook for 2-3 minutes or until fish is just cooked. scatter over most of the spring onion and dill leaves (leaving some for serving). pour over 1 tbsp lime juice and remove from heat.
9. Top noodles with fish and the pan juices. drizzle with nuoc cham dressing and add more dill or spring onion as needed.