This first U.S. outpost of a popular Mexico City brand has a modern vibe and fits neatly into the Union, a mixed-use enclave in Uptown. Its dishes are multicultural, and some are better than others. High points were our appetizers (tonkatsu-style puffs filled with Gouda and sesame-tuna tacos in a jicama shell) and desserts (bacon-topped chocolate mousse cake garnished with pretzels and generous scoops of house-made white-corn and green-pistachio ice creams, tumbling like fruit from a waffle-cone cornucopia. Less impressive: heavy truffle-oil fettuccine and the Miami: buttery bits of sautéed lobster served in a bready submarine bun rather than the usual top-split New England–style roll.