1. Pat the snapper dry with paper towel, both inside and out. If your fish is slightly too large for your wok, use kitchen scissors to cut off the tail. Make 3 deep diagonal cuts in the snapper fillets on both sides. Sprinkle fish with salt and lightly coat with flour.
2. Fill one-third of a wok with oil and place over high heat. Once oil reaches 180°C, slide fish into hot oil. Use a spatula to carefully scoop hot oil over the fish as it cooks. After 2-3 minutes, turn fish over and cook for a further 3-4 minutes or until golden and cooked through. Drain on paper towel and keep warm.
3. For the 3-flavoured sauce, use a mortar and pestle to pound the chilli, garlic and salt to a rough paste, you still want chunks of smashed chilli and garlic. Set aside. In another bowl, combine the tamarind, fish sauce and sugar stirring to dissolve the sugar. Set aside.
4. Carefully pour off most of the oil in the wok that you used to cook the fish in, leaving about a ¼ of a cup. Return the wok to the heat, add the chilli and garlic paste and cook for about 2 minutes, making sure to scrape up any crisp bits of fish from the base of the wok. Add the tamarind mixture and let the sauce bubble away for 2 minutes.
5. Place snapper onto a serving place, pour over the sauce and top with the spring onion. Serve with steamed rice.