once the beef has marinated heat your wok or pan and add the cup of oil and heat then add the beef , handfuls at a time as not to stew it , and fry until it changes colour then remove from wok and drain on paper towel . once all the beef is done clean out your wok with paper towel , return it to the heat and add 2 tablespoons of oil to the wok to stir fry with , once hot add the garlic and fry briefly then add the carrots , capsicum/pepper , onion , celery and cucumber and fry briefly again then push the vegetables to the side of the wok as to make a well now add your pre made sauce to the middle of the wok and bring to the boil , stirring till it thickens slightly and then add the sugar and stir , finally add the beef back to the wok and mix to combine with the sauce and vegetables to coat all . serve hot , serve with rice or chinese noodles . enjoy . :-) .