By Colette Bennett Taco Bell sides now feature a traditional fast-food favorite. Like most fast-food chains, Yum Brands’ (YUM) – Get Yum! Brands, Inc. Report Taco Bell relies on changing up its formula to keep customers coming back. And while many have joked that all the brand really does is rearrange the same ingredients, that formula has kept customers coming back for decades. So clearly it’s doing something right. Its most recent changes include tweaks to its $5 Breakfast Box and introducing $10 Cravings Meals, as well as announcing the return of its much-beloved Mexican Pizza. It also anno…