By DCist contributor Mike Roscoe They may have problems managing income inequality in their post-independence, Hacienda-style economies, or dealing with the lingering social effects of the brutal military dictatorships of the past, but there is one thing that South Americans have got down pat: grilling meat. As skilled and deft as any Texan tending smoking mesquite, South Americans know how to raise it, season it and cook it. From the churrascarias of Brazil to the…