Shell and devein prawns, leave the tail and the last shell segment attached.
Fry sesame seeds in a heavy-based pan over a medium heat, until seeds are "toasted".
Place prawns, cornflour and lemon pepper in a bowl, toss until evenly coated.
Heat 1 tablespoon vegetable oil in a wok, or a heavy-based frying pan, on a medium-high heat. Add prawns and stir-fry using a wooden spoon or spatula, just until prawns turn pink, about 3 minutes. Remove prawns from pan to a warm serving plate, keep warm.
Add remaining vegetable and sesame oil to wok with spring onions, garlic and ginger, stir-fry for 2 minutes. Add honey, soy sauce, chilli sauce and lemon juice. Bring to the boil, stirring continuously. Pour over the prawns, sprinkle with sesame seeds and serve.