As a follow up, I took the pork tenderloin and seasoned with salt, garlic powder, cumin, corriander, chili powder (Penzey's). I quickly seared it on a 700 degree Weber grill just to mark and give a little flavor (meanwhile I charred tomato, onion, and japapeno). It looked like tataki when cut into medallions.
I made a cooked salsa with the veg. I did this well before service and refrigerated the meat.
At the time of service, I sliced into medallions and quickly hit in very hot pan with butter, just to get to medium, similar to what AlaMoi suggested. I served over the salsa.
It was really good.
