I realize that this restaurant is recommended by many, but my experience there was unfortunate. In my opinion, when a restaurant claims to serve authentic cuisine it opens itself up to high expectations. Café Hidalgo does not meet them.
A friend and I went there for lunch. The ambience was an unsuccessful nod to colonial Spain/Latin America. The fixtures were dusty and rumpled. There were at least two cheap, touristy sombreros... an instant red flag of an inauthentic eatery. The sound of boxes of liquor and beer being noisely moved through the dining area to the bar, and the rattling of glass as the bar was restocked, was very distracting. The fact that they did so while we and other patrons were trying to enjoy our meals spoke volumes about their priorities.
The food was no better. The claim that it is authentic is blatently dishonest, and further cheapens the word as used to describe good food. Albondigas served as a meatball sandwich? When simply asked about the albondigas, the server readily stated that they were only a mixture of meats, and not the traditional recipe (which includes rice, onions, tomatoes, and even yerba buena). We ordered two unremarkable lunch specials, and they were served alongside a salad dressed in the thinnest and runniest ranch dressing we had ever seen.
The dinner menu looks more interesting, and perhaps it's better, but I'm not very hopeful.