So, I'm at work last week, all of a sudden I wonder what a cashew nut looks like. You know, like the outer shell. Seems it's life is more than a little nutty...

Wikipedia to the rescue....

"The true fruit of the cashew tree is a kidney or boxing-glove shaped drupe that grows at the end of the pseudofruit. Actually, the drupe develops first on the tree, and then the peduncle expands into the pseudofruit. Within the true fruit is a single seed, the cashew nut. Although a nut in the culinary sense, in the botanical sense the fruit of the cashew is a seed. However, the true fruit is classified as a nut by some botanists. The seed is surrounded by a double shell containing a caustic phenolic resin, urushiol, a potent skin irritant toxin (also found in the related poison-ivy). Some people are allergic to cashews, but cashews are a less frequent allergen than some other nuts."

"The cashew apple is used for its juicy but acidic pulp, which can be eaten raw or used in the production of jam, chutney, or various beverages. Depending on local customs, its juice is also processed and distilled into liquor or consumed diluted and sugared as a refreshing drink, Cajuína. Ripe cashew apples also make good caipirinha. In Goa, India, the cashew apple is the source of juicy pulp used to prepare fenny, a locally popular distilled liquor. The cashew apple contains much tannin and is very perishable. For this reason, in many parts of the world, the false fruit is simply discarded after removal of the cashew nut.

The urushiol must be removed from the dark green nut shells before the seed inside is processed for consumption; this is done by shelling the nuts, a somewhat hazardous process, and exceedingly painful skin rashes (similar to poison-ivy rashes) among processing workers are common. In India urushiol is traditionally used to control tamed elephants by its mahout (rider or keeper). The so-called "raw cashews" available in health food shops have been cooked but not roasted or browned."

Now you know.