The mix is chopped asparagus, chopped baby portabellas, minced garlic, salt & pepper sauteed in some olive oil to soften it up a bit.
Usually I use flank steak sliced in half to make a long thin piece to roll up, but the local podunk grocery store didn't have any so I ended up with one of there "Flat Iron Grillers". I sliced the top 1/3 almost all the way through leaving just enough to henge open. Then from the top hinge, I sliced another 1/3 back to other way doing the same for a nice long thing sliced piece of steak.
Layered with Sweet Baby Ray's BBQ, provolone, and then the mixture and rolled it, skewered it, then cooked it to a medium rare/medium. I don't have any finished photos, but it didn't survive the onslaught of the 5 people that were in the kitchen when it came out of the oven.