i am trying to organize a lunch on Saturday to celebrate a graduation. Looking not for super-fancy but good food, not stuffy, in central Philly. To give an idea of what I am looking for- I have tried mercato, osteria, amada, audrey claire, 20 manning and it cantuccio; however none of these restaurants are open for lunch. Any ideas? If not, is there a good deli near Rittenhouse Square -somewhere to buy some nice things for an upscale picnic in the Square?