I have no idea from whence this abomination of a recipe came but I'm guessing that it originated on the back of a chicken noodle soup packet in the 60s rather than from anywhere near China.Which has me wondering, why was it acceptable to cook a meal using MSG-filled powdered soup and not just use straight MSG?

As a coincidence, this year MSG gets its letter from the Queen.

In 1908, while searching for a method for commercializing the flavour of dashi seaweed stock, Dr Kikunae Ikeda from Tokyo Imperial University uncovered a technique to obtain crystalline monosodium glutamate. This was the core of dashi flavour: not bitter, salty, sour or sweet. He named this fifth basic taste umami after a Japanese word for "delicious". Ikeda was not the first to describe the flavour – French gastronome Brillat-Savarin used the term "osmazome" to describe what "gives game and venison its peculiar flavor" in 1825. Mandarin speakers have been calling the same taste xiānwèi (鲜味) for even longer. Unlike the other terms, umami gained traction in the English language.

Umami is a flavour that has always been prized. Asparagus, tomatoes (especially their seeds) are packed with the rich glutamate. Cheeses like parmesan are full of them. It is the amino acid that slowly builds up in jamon iberico over its two year curing process and in the shorter fermentation of olid Southeast Asian fish pastes such as prahok, nam pla and padaek. Free glutamates are what makes Vegemite, Marmite and Worcestershire sauce so addictive. Vegemite alone is 1.4% glutamate.

Commercial production of MSG began in 1909, lead by Saburosuke Suzuki who went on to found the business synonomous with MSG, Aji-no-moto ("essence of taste"). The first MSG was derived from dashi, just as Ikeda had patented but later was processed in gigantic quantities by fermenting beets, starch or sugar, as it still is today at a quantity of roughly 1.5 million tons per annum. Processed food manufacturers were quick to discover that MSG could simulate the flavour of more complex and expensive foods: why use veal stock or parmesan cheese when a cheap and virtually indestructible powder could suffice and bulk up a weak product?

In the Australian industrial food system, it weaves its way into most processed foods (and chicken noodle soup) as Flavour Enhancer (621) or as something beginning with the words hydrolyzed vegetable protein, autolyzed yeast or in the case of Vegemite, "yeast extract". For a foodstuff that is used in a prodigious manner, MSG remains socially unacceptable as an additive to Western home cooking. The MSG stays hidden because of the "Chinese Restaurant Syndrome" scare in the late 1960s; a myth that still persists today.

In 1968, Dr R.H.M. Kwok published a chatty letter in the New England Journal of Medicine regarding hearsay evidence that between 15 minutes and two hours after eating at Chinese restaurants, some people experienced "numbness at the back of the neck, gradually radiating to both arms and the back, general weakness and palpitation". He posited that the cause could be any combination of alcohol, salt or MSG. The blame fell on MSG without any further evidence and "Chinese Restaurant Syndrome" was born. It was a much more palatable explanation than drunkenness or an excess of salty snacks.

In the subsequent 40 years, it is impossible to find a study to back Kwok's letter. The latest Australian safety assessment of MSG concludes that MSG alone is not causing the problem:

There is no convincing evidence that MSG is a significant factor in causing systemic reactions resulting in severe illness or mortality. The studies conducted to date on CRS (Chinese Restaurant Syndrome) have largely failed to demonstrate a causal association with MSG. Symptoms resembling those of CRS may be provoked in a clinical setting in small numbers of individuals by the administration of large doses of MSG without food. However, such affects are neither persistent nor serious and are likely to be attenuated when MSG is consumed with food. In terms of more serious adverse effects such as the triggering of bronchospasm in asthmatic individuals, the evidence does not indicate that MSG is a significant trigger factor.

I'm not sure how much MSG-packed, umami chow mein I'll need to serve to convince people that MSG is OK in strict moderation. My vain hope is that it will be less than another 100 years worth.