Eric really liked the marinade on this recipe that I found at Cooking Classy. It was pretty enjoyable, but if using sirloin steak, try to get quality sirloin so it isn't chewy. I would love this with something like tenderloin.
**This makes our place very smoky if using on the cast iron griddle. It also leaves a sticky residue from the olive oil that takes a lot of time to clean. Would be better on an actual grill.