When the yen for Mexican (not Tex-Mex) food strikes you, try Guajillo’s. Lunch specials offer soup (fideo or a spectacularly punchy tortilla) followed by a choice of entrees, which run from steamed cod with a tomato-serrano sauce to an astonishingly tender bistec a la mexicana. Dinner choices are a bit more elaborate (chicken breast with mole verde, steak with pasilla chile sauce) but no less authentic. Often crowded and noisy at lunch, Guajillo’s mellows out in the evening. (8/13)