Not quite a year old, Union has managed to root itself so deeply into South End culture, you’d think it has been around for decades. What’s the secret? We suspect it has something to do with co-owner Jeff Gates’ genial nature, executive sous chef Josh Steinberg’s steady hand with mostly local ingredients, and bartenders who know their way around the many bottles they shake, chill, and pour with such profound dexterity. Or maybe it’s simply Union’s mix of unpretentiousness and sophistication. Whatever the draw, few who drop into Union can resist coming back—and fewer still believe it isn’t here to stay.