1. Cut hairy gourd in half. Peel skin and cut in thin slice. Dice tofu. Beat the egg.
2. Cut beef in strips, marinate with marinade. Heat the oil, stir fry beef. Put in hairy gourd and 800ml of boiling water. Put in tofu. Cover the lid and cook in mid-heat for 5 minutes.
3. Open the lid, season with salt and sugar. Take out excess oil. Put in egg and green onion.