To Make Sweet and Sour Tamarind Sauce
Combine all the ingredients in a small heavy-based saucepan and stir over medium heat for 5 mins or until thickened. Keep it warm.
To Cook
Heat vegetable oil in a deep-fryer or large heavy-based saucepan, deep-fry the fish for 8 mins. Drain the fish on paper towel.
In a large bowl, add shredded coconut, fried garlic, fried red shallot, lemongrass, some red chillies, kaffir lime leaves, then add part of sweet and sour tamarind sauce and mix well.
Place barramundi fillet on a serving plate, drizzle with the sweet and sour tamarind sauce, put all of the crispy herb salad mix onto the fish then serve.