Place the chilli, spring onions and coriander in a food processor and pulse until chopped. Add the curry paste and fish sauce, then pulse again to mix. Add the fish, crab meat and egg and pulse until the mixture is well mixed but not smooth. Using wet hands, shape the mixture into 8 crab cakes. Cover and chill in the refrigerator for 10 minutes.
Meanwhile, mix together the dipping sauce ingredients and set aside. Soak the noodles in boiling water for a few minutes to soften. Drain and rinse under cold water, then drain again and place in a bowl. Add the sugar snap peas, carrot and a little of the dipping sauce and mix well.
Heat the vegetable oil in a frying pan, add the crab cakes and cook for 5 minutes, turning once, until golden and cooked through. Drain on kitchen paper and serve with the noodle salad, dipping sauce and lime wedges.