This small-plate BYO stays loyal to its popular dishes, for better or for merely good. Half the menu consists of seasonal creations, and the other half never changes. Excellence is scattered throughout both categories, along with less exceptional efforts. All dishes show attention to textural contrasts, but for every standout, such as the pork ribs with honey-pasilla sauce, radishes, crema, and queso fresco, there’s a plate-filler, such as the bland but serviceable mushroom empanadas. By and large, though, Chilam Balam sets a high bar in a basement restaurant. Servers are attentive and soft-spoken. Let them concoct margaritas from your tequila.