There's a wide variety of mezcal and sotol to choose from at Barra, a small Mexico City-inspired bar and restaurant in Union Square. If you’re interested in learning about those drinks, there’s probably no better place to do so in Boston - the sipping flights are a respectable $24 each. The food, on the other hand, is a little pricey (two tacos for $16, for instance). We appreciate the house-made blue corn tortillas and cured beef, but the smaller portions make eating here feel more like a snack than a full dinner.