Trim all fat from steaks; cut each steak in half. Heat butter and oil in a heavy-based frying pan.

Cook steaks over high heat for 2 minutes; turn over and cook for another 2 minutes or until done to your liking. Remove steaks from pan, cover and keep warm. Add green onion to the pan, stir for 3 minutes, add mushrooms and stir for 3 minutes or until mushrooms are soft.

Combine cornfour with 2 tablespoons of wine to form a smooth paste. Stir into remaining wine and add all at once to the mushroom mixture. Cook until mixture boils and thickens. Stir in parsley. Place steaks on serving dishes. Spoon sauce over fillets; serve immeadiately.