There is no actual barley in the noodles. The name is an allusion to how small the noodles are, as in as small as a grain of barley.
The noodles are made from wheat flour, eggs and salt, that is mixed together and kneaded into a smooth dough.
The dough is rolled out very thinly and cut it into very thin strips. It is then cut into small pieces the size of a grain of barley, or, you can form the dough into balls, let stand until firm (about half an hour,) then grate the balls coarsely.
Either way, you then let the noodles stand on trays to dry out.
Hungarian Egg Barley can be boiled up in water, or braised in a broth and served in the broth. To braise it, you sautée it in some butter, add broth, and then simmer until the liquid is all absorbed. When braised, it will have the consistency of rice when cooked.
Hungarian Egg Barley can be dried for storage.
Hungarian Egg Barley is called “tarhonya” in Hungarian.