A beef jerky is the act of giving or receiving a handjob using ground beef as a lubricant. Usual one would use saliva or some sort of lube for a handjob; a beef jerky requires uncooked ground beef.
Why do you ask? Say your camping, forgot to bring lube and both you and your partner have the pasties. Look no further then a pack or room temperature ground beef.
You can also use other ground meats.
If your partner vigorously jerks fast enough this will create enough heat to have a meal after sex.