As authentic as it gets!
If you happen to be in Amizmiz (or in Marrkech, which is only a cheap 1hr. bus ride away), I'd suggest checking out the Berber Market which takes place in Amizmiz every Tuesday. All the Berber villagers from the remote mountain villages come down to Amizmiz to sell their goods, stock up on supplies, catch up on the news, socialize, and generally have a good time.
Let me be frank: it's not glamorous. Nor for those who get uncomfortable easily. You'll probably be the only Westerner there if you go in the off-season, and you might get some curious stares. But, all in all, it's good, safe fun. The market is divided into sections of meat, produce, dry goods, clothes, stationary, barbers, animals, donkeys, used goods, and just about everything else you can imagine, all complete with the lurid colors and smells you'd expect of a weekly Berber market in a place like Amizmiz.