Place the fish, fish sauce, curry paste and sugar in a food processor and whizz until smooth. Stir through the green beans and coriander, then season.
Brush a 12-hole muffin tray with the oil, then spoon 2–3 tablespoons of the mixture inside each hole. Lightly press down. Place in a preheated oven, 200°C (400°F), Gas Mark 6, for 12–15 minutes until golden and cooked through. Serve with sweet chilli sauce and cucumber wedges.