BALI (AP).- Off Bali’s beaten track, past a towering banyan tree and next to an ancient Hindu temple, the world’s largest bamboo commercial structure is slowly taking shape: a chocolate factory. The three-story, 23,000-square-foot building — made from more than 3,000 long, flexible poles — is crowned with a graceful, sloped ceiling nearly 50 feet high. Frederick Schilling, co-owner of the Big Tree Farms factory, calls it his “bamboo cathedral.” The tropical plant, favored in the West for flooring, furniture and household accessories, is increasingly being touted as the construction material of choice by green advocates from South America to Africa. Bali is leading the charge, attracting carpenters, architects and designers from across the globe to use bamboo in building everything from a school and luxury villas to exclusive resorts. The plant, found in almost every equatorial nation, can grow up to 4 feet in a single day