Anthimus was a physician who lived during the 6th century CE, not a gourmand. The "letter" is essentially health advice; a kind of primer for foods to eat and foods to avoid in accordance with the accepted medical doctrine of his day. He wrote in Latin, and his letter is addressed to King Theuderic, then King of the Franks. Grant believes that he lived at the time in northern Gaul in Theuderic's court, though Grant's introduction indicates that this position is open to debate. One thing that is consistent with Grant's theory is that some of the spices and foods referenced in the letter would have been rare and expensive in 6th century Gaul.
The tenor of Anthimus's advice is interesting, not only for the fact that it implies that a rich Gaul had access to a surprising variety of foods (including pistachio nuts!) but also for what a healthy diet might be deemed to include and what modes of food preparation were deemed best. A few examples will have to suffice:
At this point I will explain how bacon may be eaten to the best effect, for there is no way that I can pass over this Frankish delicacy. If it has been simply roasted in the same way as a joint of meat, the fat drains into the fire and the bacon becomes dry, and whoever eats it is harmed and is not benefitted; it also produces bad humours and causes indigestion. But if bacon that has been boiled and cooled is eaten, it is more beneficial, regulating constipated bowels and being well digested. But it should be boiled well, and if of course it is from a ham, it should be cooked more. None of the rind should be eaten because it is not digested. Bacon fat which is poured over some foods and vegetables when oil is not available is not harmful. But frying brings absolutely no benefit. (p. 55)
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Whenever hard boiled eggs or eggs cooked in vinegar are used in a sauce, only the yolk should be eaten. For if the white is made hard, it is not digested well, but causes diarrhoea, and rather than being beneficial is harmful. And so beware of hard egg white. Egg yolks that ar runny are agreeable to the body, so my authorities inform me. (p. 65)
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Cheese, so my authorities tell me, troubles not only sick but also healthy people, particularly those who suffer from problems of the kidneys and those affected with spleen, because it congeals in the kidneys and as a consequence stones are formed.
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But fresh sweet cheese which is unsalted is suitable for healthy people. However, if it is extremely fresh it is good to dip it in honey. (p. 79)
Overall, Grant's book is a fascinating look at what constituted "healthy" and what constituted less than healthy foods, cooking and eating habits during that period when classical Roman learning was beginning to give way to the medieval world. I recommend it for any Roman scholar or medievalist.
Grant, Mark, ed. Anthimus. De Observatione Ciborum: On the Observance of Foods. (Prospect Books (UK), August 30, 2007). ISBN-10: 1903018528. ISBN-13: 978-1903018521.