Smack dab in the center of the Loop is a restaurant that the likes of which for too long have been relegated to other areas of town. Open from power lunch time to after-theater munchy time, 312 has, among other things, some of the largest tables I've had the pleasure of dining off of. The ambience is scotch whiskey, perhaps even bourbon, more than martini, and although you're probably here for the company, the upscale American cuisine is excellent.
The door is on LaSalle at the corner of Randolph, a million miles from everything except for the theater next door. A fringe benefit of 312's location is that while traffic in River North crawls on weekends, traffic in the Loop is non-existent after 6 p.m. Friday. A nice find, and a great place to go if you can remember it next weekend.