At Union Square Cafe, Lena Ciardullo Turns Vitello Tonnato Into a Sandwich

One of Italy’s most recognizable appetizers, vitello tonnato—hailing from the northern region of Piedmont—has a very specific look: a plate of thinly sliced veal slathered with a rich, tuna spiked mayonnaise and drizzled with capers for a little tang. What it doesn’t look like is a New York-style sandwich, and that is exactly how Executive Chef Lena Ciardullo is serving it at Union Square Cafe.“I always...