BOSTON >> The aroma of Asian stir-fried vegetables and pork wafted through a West Roxbury home before dinnertime on a recent Saturday. And around the table, Joseph Wong, Donald Lee, Francis Chan, Wei-Li Sun, and Wayne Wang were waiting, knowing this particular dish— written on the week's menu posted on the refrigerator —was coming. The table had been set by Wang, 22, and the kitchen sweep-up would later be done by Chan, 34, part of their assigned chores also listed on the refrigerator.