Take a whole backstrap and roll/slice it out like a pork tenderloin to make it flat, then pound it to about a 1/4 inch thickness all the way around. Fill with onions, jalapenos, and pepper jack cheese. Roll back up and wrap in bacon, use toothpicks to secure the bacon. Grill or smoke until you hit an internal temp of about 150-155. DELICIOUS.

Roughly something like this....