Despite their bum rap, chains can be good, like when you're traveling and don't want to risk trying the local cuisine, or when you're traveling and don't want to risk letting your uncle escape your basement. For a chain you'll have a hard time freeing yourself from, hit Rosa Mexicano. The NY-based, south-of-the-border behemoth just planted its 14th flag in Southie, offering upscale Mexican and specialty drinks in an area that now has three fancy places paying homage to our southern neighbors. So as to keep it straight from the others, here's what you need to know: The Setting: Point out exactly where you cruised by on your mini speed boat tour from the 130-seat patio that overlooks the harbor or, like Vin Baker circa 2002, take it inside to the colorfully mosaic'd 10-stool bar or dining room accented by blue tiled walls cascading water and featuring 75 cliff diving figurines seemingly jumping off of them. The Sippables: Complain about your boss's awkward neck massages over a handful of recognizable Mexican suds, micheladas, and sangrias, before getting to the point where you start giving other people neck massages after a couple signature margs, like the La Única (1800 reposado & Grand Marnier), or cocktails that include an El Mezcalito with fresh strawberry and jalapeño-infused tequila. The Sustenance: After noshing on tableside guac and small bites like lump crab empanadas, and garlic-epazote fries w/ mole, move on to one of seven types of tacos (seared diver scallops & crisp Kurobuta pork belly w/ habanero salsa) and entrees like the crispy marinated pork shank w/ chipotle creamed spinach & red bean-chorizo chili, which, unlike your uncle, is supposed to be off the chain.