I sometime get some tough pieces of meat, but I read that one can use KOJI, a japanese ferment (mold/yeast?), made to make sake, miso, but it's also used in Japan to tenderise meat and fish... Well, not sure if this is paleo... And, I am not sure if the mold itself is safe to ingest raw. Sure, I plan to scrape off the outer layer when it's done, but there might be some left... I suppose the japanese don't eat the meat raw, anyway, I'll give it a try once my koji ferment arrives. Supposed to be very simple, takes just a few days.
Another thing I was thinking is Gravlax, a swedish/scandinavian technique of marinating fish with dill/herbs/black pepper, some salt and sugar/ honey), making the fish more tender, was thinking if it might work with another fatty fish as well...
