Oyster sauce salt, should be added to the sauce, since the oysters should provide all the savoury flavour. However, this method is prohibitively expensive. Many modern oyster sauces are thickened with cornstarch, flavoured with oyster essence or extract and darkened with caramel. Vegetarian oyster sauce prepared from mushrooms, often oyster mushrooms or shiitake mushrooms, is also popular and generally lower in price. It may contain more taste enhancers if less mushroom extract is used to reduce costs. Most of the oyster sauces available on the market contain added monosodium glutamate (MSG). In recent years MSG-free varieties can also be found. The taste
Portobello Road "The Blue Lamp", starring Dirk Bogarde and Jack Warner, as P.C. George Dixon, a character later revived in the long-running TV drama, "Dixon of Dock Green", featured location filming in the Paddington / Notting Hill / Portobello area. It features good shots of these locations in pre-Westway days, and includes a thrilling car chase along largely traffic-free roads, including Portobello Road. In the short story "The Portobello Road", Muriel Spark narrates the story of a murderer who, visited by the ghost of his victim, Macbeth-style, tends to constantly go to the Portobello Road market to meet her. "The Portobello Road"