1. To make the sauce, place the coriander root, chillis, garlic, ginger, eschalots and oil together in a food processor and pulse ingredients to a smooth paste.
2. Heat a medium saucepan over a medium heat, add paste and cook for 2 minutes or until aromatic.
3. Add tamarind paste, sugar and fish sauce with 80ml water, stirring to combine. Cook for 3-4 minutes or until reduced by a third. Remove from heat and check balance, adjusting accordingly so that the sauce is sweet, sour, hot and salty.
   Set aside for later.
4. Meanwhile, heat oil in a wok over a high heat, (about a third full), until a piece of bread sizzles and becomes golden.
5. Score the fish from the head to the tail, at 1cm intervals, cutting through to the bones.
6. Evenly coat the fish in the rice flour, removing any excess.
7. Carefully slide the fish into the hot oil and cook for 5 minutes each side or until skin is crispy and fish is just cooked.

To serve, place half the sauce down the centre of a platter, place the cooked fish on top and spoon the remaining sauce over the fish. Garnish with chilli, spring onions, fried shallots, coriander leaves and lime juice.