thinly slice beef and marinate in 1 tbspn cornflour, 1tbspn oyster sauce, 1 tbspn soy sauce, 2 tspns whisky (I used bourbon...), 1 tspn minced garlic.
prepare the sauce by mixing 1/4 cup tomato sauce, 1 1/2 tspns chinese rice wine or dry sherry, 1 tspn soy sauce, 1/2 tspn worcestershire sauce, 1 tspn sugar.
stir fry beef in oil and remove from wok. stir fry your veg of choice (he uses onion, celery, green capsiucm, button mushrooms.
add sauce and 1-2 tomatoes cut into wedges. add beef and bring to boil.
simple. very tasty. i love tomato in asian dishes.