Mendocino Farms is the budding fast-casual sandwich concept with a localish ethic and a haute cuisine aesthetic. Try not to be overwhelmed by all the choices. Chipper servers will walk you through the tough decisions: sandwich or salad, traditional or esoteric, grilled buckwheat or rustic white bread. Anything can be replaced by anything else. Try, even harder, not to be undone by fillings like "tempeh bacon," a strip of seeded, rubbery tire tread that does double duty by insulting both tempeh and bacon. Despite all the customization, the most popular sandwich might be the banh mi that veers so far from the archetypal Franco-Vietnamese sandwich, it's served on a ciabatta. The sandwich hits dead-center, and the effect is just right: meaty, spicy, crisp and moist, hearty but not overwhelming.