1.Shell and devein prawns.
2.Blend or crush 2 tablespoons of the seeds to a coarse powder; transfer to small bowl. Stir in the water, peanut butter, vinegar, sauces and sesame oil.
3.In a medium saucepan of boiling water, cook noodles until tender; drain. Rinse under cold water; drain. Combine noodles, cucumber, capsicum, onion and sesame seed mixture in medium bowl; season to taste.
4.Meanwhile, heat half the peanut oil in wok; stir-fry chicken, in batches, until cooked. Remove from wok.
5.Heat remaining oil in wok; stir-fry prawns until changed in colour. Stir chicken and prawns through noodle mixture; sprinkle with remaining seeds.