Stir-Fry Beef and Vegetables

1 t cornflour
½ C beef stock
2 T oyster sauce
2 cloves garlic
1 t caster sugar
2 T peanut oil
350g rump steak, finely sliced
250g beans
1 red capsicum, sliced
½ C bean sprouts, tails removed

Dissolve cornflour in a little of stock, add remaining stock, oyster sauce, garlic, sugar, set aside. Heat oil, add beef 2 mins or until browning. Add beans and capsicum 1 min, add sauce and cook until boils and thickens. Serve on rice or noodles.