Papito (Connecticut and 18th) has been giving their chef his head on the weekends (at least) to offer some Mexican specials that have been truly delicious and sometimes stunning. Tonight was lovely light housemade tamales with roasted peppers and cheese, topped with a lightly vinegary red cabbage, pico de gallo and crema fresca. Really nice. The desserts have been out of the ordinary too, with the special being a delicious pilloncillo bread pudding wth creme anglaise and chocolate sauces. I'm not usually a dessert person, but this was good -- and they make one of the few flans I've ever liked, as well (on the regular menu).
Haven't tried it yet, but weekends now have posole as a regular item. Another special a few weeks back was an exceptionally soulful birria, with melt in your mouth beef in a great rich broth. Made an exceptional taco filling -- the beans and rice that come with many of these are unfortunately forgettable.
317 Connecticut St, San Francisco, CA 94107