The auroch, which is what modern cattle are derived from used to be a primary food source for many people across the old world as it had a wide range of habitability stretching from the edges of Western Europe all the way to Korea and Southeast Asia. It is believed that they were first domesticated around 8000 years ago but have been known and hunted by mankind for much longer. Some Cro-Magnon cave paintings such as the one at Chauvet Cave display pictures of aurochs running as a pack together with other ancient animals. The animals were left to wander and do auroch things for the majority of their existence but as the human population began to explode with the rise of the Roman, Han, Mauryan and Seleucid empires, this left little room left for the aurochs to graze. This population explosion also necessitated a much greater degree of hunting and because there were no regulations 2000 years ago they were hunted so prolifically their population began to decline so that by 1200 CE their range had decreased from most of Eurasia to just the forests and swamps of small patches of Eastern Europe. The last living aurochs lived in these remote forests in Poland where the government actively kept track of them recording 38 in 1564. Unfortunately the population was already in such a devastated state that the last auroch died in the Jaktorów Forest in 1627. There are initiatives in place to try and decode the auroch DNA sequence and hopefully one day bring this animal back to life but for the time being the auroch is a foodstuff that modern people will never be able to taste.

Sources:

Retracing the Aurochs: History, Morphology & Ecology of an Extinct Wild Ox

The origin of European cattle: Evidence from modern and ancient DNA

History of the Aurochs (Bos Taurus Primigenius) in Poland

Edit: I can't grammar very well

Soma, the pre-war and celebretory drink that turned men into gods, and to which a very large portion of the oldest Vedic text in existence, the Rig Veda is dedicated, is currently classified as a brew derived from a unknown plant.

It is now widely believed to refer to a fermented cannabis derivative, but academics still do not agree on all counts.

Source:

Swamy, B.G.L., The Rg Vedic Soma Plant, Indian Journal of History of Science

The Rgvedic Soma, Dr. N. R. Waradpande (1995)

Mukherjee, B. L., The Soma Plant, JRAS, (1921), Idem, The Soma Plant, Calcutta, (1922), The Journal of the Royal Asiatic Society of Great Britain & Ireland 1921

Falernian wine is just wine, however. I'm not so sad that it's lost because you can probably get the feel of opening a skin of Falernian by drinking a bottle of expensive wine, even if the taste isn't identical. I'm more curious about a different lost aspect of Roman cuisine.

The Romans also had a fermented fish sauce called garum that they put on everything. I mean everything, from peacock to honey cakes. They left some recipes but when modern people try to follow them the results are universally disgusting. We will never taste authentic garum, and that is a damn shame.

Dodo kebabs are not ever going to be on the human menu again. However, by many accounts that is probably a good thing except for the unfortunate Dodos.

Their flavor had been described as unwholesome and greasy, "it was clearly an acquired taste as the (dutch) sailors named it 'valghvogel'- meaning disgusting bird.".

It wasnt so disgusting that no would eat it but there's good evidence that it was wiped out as a food source by non native predators. there is also a case to be made that since two birds were potentially capable of feeding the entire crew of 1 ship that the disgust felt for the bird may have been augmented by a menu that consisted of too much Dodo.

Sources

The Rules of Extinction by Robert Kanigel

(Behind a pay wall, sorry) https://www.newscientist.com/article/mg13918884.300-justice-at-last-for-the-dodo/

Silphium.

Pausanias, Guide to Greece, lists it as a major export of Cyrenaica, a Greek colony that controlled coastal Africa west of Egypt. It was even the chief design on their coinage. It was a strong, hot flavour, that is often likened to horseradish or asafoetida. The last sylphium plant was presented to Nero as a curiousity.

Its extinction is due to it never being domesticated. It was wild-crafted, as they say nowadays: encouraged to grow in its natural places, but never really cultivated. Then demand started to push past supply (and they were charging through the roof for it), and someone decided animals fed on it by pasturing in the area were an extra treat, and with a little help from some climate burps they extincted it.

I don't think we're missing much, but I don't like asafoetida.

How does this not count as a "throughout history" question. I get tons of questions removed for being too broad or trivia-based, but this one gets through? Why?

By spear is kneaded the bread I eat,

by spear my Ismaric wine is won,

which I drink, leaning upon my spear.

-Archilochus (680-645BCE) (translation Richard Lattimore)

Ismaric/Ismarian wine is one of the first named wines and this short poem by Archilochus has always piqued my interest. It's also mentioned/used in the Odyssey to get Polyphemus drunk. It's a wine from Thrace and was drunk undiluted, in the odyssey it's mentioned that it should be drunk at a ratio of 20/1 water/wine so as not to get drunk.

here is an interesting paper on Archilochus: http://community.middlebury.edu/~harris/Archilochus.pdf

One thing is the original scallions, which were one of the things that made the ancient city of Ascalon famous. Theophrastus was the first to describe the small onion of Ascalon. Three hundred years later, Pliny the Elder described some small onions growing in Roman gardens as "onions of Ascalon", though his description sounds more like a shallot than a scallion (see Griffith, Linda, and Fred Griffith. Onions, Onions, Onions. Boston: Houghton Mifflin, 1994, p. 52). However, despite the name deriving from the name of the city, and it being world-famous at the time, the exact species has been lost to time, and bred into many different kinds of onions.

We don't have a recipe for the black broth the Spartans ate, although there is no reason why if you didn't try enough combos of the ingredients you might get it right by accident.

garum.

Vietnamese fish sauce is said to be close but no one knows for sure.

Hey, I'm only seeing this late, but I would challenge your premise! Firstly, falernian wine is nothing more than a white wine grown in an area of northern Campania. It is fairly common as a mid-to-high range Italian wine today, so even if you aren't drinking ancient style wine, you can absolutely have some Falernian.

But stylistically, of course, modern wines are rather different than ancient ones (just to name one difference, ancient wines were not filtered). Recently there have been some attempts to recreate authentic ancient style wine, probably the most interesting of which is the Villa dei Misteri vineyard, which makes wine from grapes grown in Pompeii and tries to follow ancient methods. Apparently it is a bit too strong for modern tastes.