El Árbol is a vegetarian restaurant that offers many vegan options, a status supported by multiple HappyCow reviews and the venue's own listing. It is not 100% vegan, as reviews note it is "not 100% vegan" and "not fully vegan." The owner and staff appear to be vegetarian or vegan-friendly, and the kitchen is accustomed to vegan preparation. Several vegan reviewers report positive experiences with dishes such as tofu curry, vegan ramen, and vegan pizza. Tier B is appropriate because the venue is insider-led, with a vegetarian or vegan ethos and dedicated practice.