1.Blend or process fish, sauce, kecap manis, garlic and chilli until smooth. Combine fish mixture in large bowl with beans, shallots and coriander; shape into four patties.
2.Cook patties on heated oiled flat plate about 15 minutes or until cooked. Transfer to a heatproof plate and keep warm.
3.Combine spinach, cucumber, juice, sugar and extra sauce in medium bowl.
4.Split buns in half; toast cut sides. Sandwich salad, patties and sweet chilli sauce between bun halves.