He invited us to share his dinner during Sarakosti, that is, one of their fasts, and shared with us what delicacies he had. During their fasts these monks eat no fish that has blood: at those periods they have to live on herbs and other such fasting stuff. He served us rocket, celeriac, heads of leek, cucumbers, onions and nice little green garlic shoots. They get all of these from the communal monastery gardens, and some have their own individual gardens too. We ate these herbs raw, without oil or vinegar. That is their regular diet. He also served us black conserved olives (which they call Demarties), black biscuit, and wine. They eat biscuit because they rarely have occasion to fire an oven. He called two companions, who brought some salt and dried fish, squid, octopus and ca**erons. During a fast they can eat all kinds of crabs, sea-slugs and shellfish such as mussels and oysters because they have no blood ... They always start their meals with raw onions and garlic; their main dishes are salted olives and broad beans soaked in water, and they finish with rocket and cress. Whatever their health or constitution they do not mix water with their wine ... It is not only the monks who choose to live like this but the priests and other churchmen of Greece and also the common people, who during their fasts would not eat fish with blood or meat or any other inappropriate food even if they were to die for lack of it.
Pierre Belon, Les observations de plusieurs singularitez et choses mémorables trouvées en Grèce, Asie, Judée, Égypte, Arabie et autres pays estranges (Paris, 1553) book 1 chapter 48.
The French text is on this page and the next