The cast of Mad Men would feel right at home here. The lighting is low, the bartenders make a mean martini, and the menu includes a mix of the old school (iceberg wedges draped in blue cheese dressing) and the modern day (tuna tartare with avocado and Thai chili sauce). Sides like creamed spinach and mac-and-cheese are à la carte additions to main courses that include prime rib with house-made horseradish and Chilean sea bass. (The Best of Prime menu, $35 for four courses, is a popular alternative.) Tuesday’s “Pasta With Frank” promotion includes live music inspired by the Chairman of the Boa