The spiffing up of Avenue A takes a giant leap with Yerba Buena’s ambition. Just hatched, the kitchen quickly grooving, it’s already winning regulars. I’ll brave the street’s remnants of grunge for serious cocktails by a professional barman, grown-up impresarios determined to please, and fabulous Latino food, reasonably priced, by partner Julian Medina, whose cooking I loved at Toloache. I’m a pisco-sour fan, and I recommend this outsize version in a soup-bowl-size goblet with its froth of organic egg white ($11). The guacamole ($9) is good enough, the house-made chips are fantastic (though too salty), and we love the picada—a collection the table can share of yucca croquetas, tostones, pork rinds, and chorizo chunks to dip in a spicy sauce. Except for cornmeal-crusted calamari and sweet plantains overwhelmed by sticky, sweet tamarind, our fussy foursome would be thumbs-up all night if we weren’t so busy eating. The ensalada of jícama, avocado, tomato, and orange in a tangy citrus vinaigrette with minty yerba buena. Baja-style grouper tacos with jícama-cabbage-and-chipotle slaw. The savory seafood fideua baked with small macaroni. Malbec beef short ribs with hand-cut shoestring fries. And tonight’s special parrillada, sensational mixed grill with rib eye, chorizo, short ribs, and chimichurri. It’s all delicious. I’m not a churros hound, but the fanatics are devouring these. Our friend, a spirits writer, shares sips of a dessert wine, Alcyone, and insists it tastes like s’mores.