heir·loom/ˈe(ə)rˌlo͞om/ – noun: A valuable object that has belonged to a family for several generations. With Heirloom, veteran chef Al Paris and proprietor Robert Bynum (of Warmdaddy’s and Relish fame) bring upscale comfort food to the quaint neighborhood of Chestnut Hill.  At the 50-seat BYOB, the menu reveals a thoughtful focus on…