What is Mountain Oyster?
1.
Beef testicles battered and fried; considered gourmet dining in the American west even though they are tough and have gristles.
The Brown Derby parboils their mountain oyster dishes so they won't be so tough and hard to chew.
2.
most likely originated in Australia or new Zealand, due to one of the main livestock being a sheep
A sheep's testicles
You can't eat mountain oysters...unless you're into that.