Based on recent discussions about steak tartare and turkey burgers http://chowhound.chow.com/topics/6429..., I did sandwiches with a carpaccio-like preparation of extremely rare grilled steak with lots of wilted arugula, fresh garden tomatoes, chopped scallions and chopped calamatas. This with a strong, garlickey romoulade as dressing.
I ran out of capers (usually a staple), so I used calamatas. I didn't see the need for pancetta and quite frankly, I forgot cheese.
This was a delish sandwich though hard to keep together. It would have worked better done more coarsely, with sliced vidalia onion or put in a sliced open French roll. More capers could be in the dressing.