Worcestershire sauce
Cantonese sweet and sour sauce is the direct ancestor of sauce of the same name in the West, and originally developed for sweet and sour pork. The late renowned chef from Hong Kong, Leung King, included the following as his sweet and sour source sauce recipe: white rice vinegar, salt, Chinese brown candy, ketchup, Worcestershire sauce, and dark soy sauce. Hong Kong's gourmet Willie Mak, himself a long time friend of Leung, suggests to contemporary eateries not to resort to cheap bulk manufactured versions of vinegar, ketchup, and Worcestershire sauce, or the sauce will risk being too sharp in taste and might break the balance of flavours. He suggests the more acidic white rice vinegar could be replaced with apple cider vinegar, and ketchup and Worcestershire sauce should be of renowned gourmet brands.