This just might be one of my summer staples. I really, really, really like cold leftover steak, it's right up there with cold leftover pizza and spaghetti. One way I like it is to thinly slice it on a salad, then dress the salad with balsamic vinegar and olive oil or with a balsamic vinaigrette.
I served it on a bed of lettuce with the veggies I had on hand and shaved some Parmesan cheese on top.
Pretty darned good.