high-extraction einkorn flour?

Just a clarification for trampled by geese: High-extraction flour can also result from old-fashioned stone grinding since the bolting (sifting) of the wheat takes place after the grain is ground into flour. But you're right that modern "whole wheat" flour is made by separating the bran and germ from the wheat, then grinding them all separately (not really "grinding" since it's done with roller mills) and putting some, but not all, of the bran and germ back into the flour. I believe manufacturers make a distinction between whole-wheat flour, which is what I just described, and whole-grain flour which is the entire wheat kernel all ground together--and much better nutritionally. Incidentally, I would be very cautious offering wheat of any sort to people with serious wheat allergies. It IS wheat, after all--probably the first wheat to be domesticated in the Fertile Crescent back in the Neolithic period. Long, long ago.

Well, not sure about the exact method. High extraction means more of the bran and endosperm are left on, so a whole wheat would be high extraction. White flour has all bran and endosperm removed, so it is low extraction. White flours and white rice are also less disruptive to your gut.

High extraction is a rating of how much flour you end up with after milling. So whole wheat flour contains the entire mass of wheat because the bran and endosperm are included in the milling. Ten lbs of wheat would yield ten lbs of flour. White or bread flour would only yield 70-75%. High extraction can mean that some of the bran and endosperm are left in the flour.

I have only heard of Einkorn flour, but have heard it's easier to digest.