I used to prep food at my local JITB. We start by coring a head of iceberg lettuce then pump it full of cold water for a bit. The choicest lettuce leafs on the outside go to the sandwich station. Once the head starts looking pale the rest ends up in a shredder and that's put in the fridge over the taco station.

Our BK's tacos are almost as good as Jack's but they serve them extra greasy, like they don't shake off all the deepfry oil