The dining room at this elegant barbecue restaurant fills up at brunchtime — which is a bad beginning to a description of Smoke for two reasons. First, the kitchen does far better work at dinner than at brunch. And second, “elegant barbecue” is not nearly the oxymoron or hipster prank that it sounds. If you’re not convinced, just go for the Big Rib, a fabulous beef rib sitting atop a cheddar-hominy casserole and garnished with chimichurri. It’s as good as anything served on butcher paper.