Let's list the individual ingredients in the roasted chicken sandwich: chicken (of course), pesto, roasted peppers, sliced tomato, and arugula. Sounds pretty tasty. You could assemble all those ingredients on two slices of bread and have a pretty good sandwich yourself. At Gran Forno, though, the sandwiches vault somehow from pretty good to great. Partly it's the bread onto which these ingredients are layered -- fresh-baked ciabatta, one of many breads Gran Forno bakes daily. Ciabatta offers a satisfying combination of good crunch on the outside and a feathery-soft interior. But it's also the proportion -- of chicken to tomato to pesto to roasted peppers. There's none of that gargantuan piling-on that Americans savor, not so much for the flavor as for the feeling that they possess more sandwich than they can eat comfortably. There's a sense of rightness, of pleasure in limits at work here that causes the ingredients to meld together into a greater oneness of sandwich than any ordinary mortal can obtain. That's why people line up to buy them on the weekends.