Heat up a wok, add two spoons of peanut oil and stir-fry the onion, garlic, ginger, celery, corn, chilli and pak choy stalk for 1 minute. Add frozen vegetables and fry for another two minutes. Fold in snow peas and stir-fry for another two minutes. Fold in pakchoy leaves and leeks. Add the mixed soy sauce and bring to the boil. Fold in the rice and heat, season with salt and serve.