Thai Beef with Mushrooms in Oyster SaucePygal

Dissolve the cornstarch in soy sauce in a bowl. Add the beef into the mixture. Leave for about 20 minutes. Remove the beef and set aside.Place a wok over a medium heat and add the canola oil. When the oil is hot, add the garlic and stir-fry until light golden in colour. Add mushrooms (both kinds), and continue stirring until the mushrooms are almost cooked. Add the beef and stir-fry until the beef is cooked through.Add the oyster sauce, sugar and black pepper. Stir well. Add the onions (scallions) and chillies. Mix well.4. Serve, garnished with spring onion leaves.