Rinse anchovies and soak for 10-15 minutes. Drain dry in a plastic colander then pat completely dry with several layers of kitchen paper towels. Toss in tapioca flour.
Heat some oil in a wok. Shake off excess tapioca flour from the anchovies and deep-fry until golden brown and crispy. Dish out and drain from oil.
Heat the sesame oil in a clean wok, fry dried chillies, onion and bird's eye chillies for a while. Combine lime juice, honey, water and fish sauce and add to the pan; bring to a boil until mixture turns frothy and thick. Return prefried anchovies to the honey sauce. Stir-fry briskly until well combined. Dish out and serve.