Drain the pineapple, reserving the juice. Combine the juice with thecornflour, soy sauce and sesame oil.
Heat the canola oil in a wok. Stir-fry the garlic, ginger and vegetables, until crisp-tender. Add the prawns and stir-fry for 2-3 minutes, until pink. Add the pineapple.
Stir the juice mixture then stir into the pan until thickened. Serves 4.