To mark this milestone, the popular fast-food chain is treating customers to a Birthday Shake and a "Kids Eat Free" offer. The shake is a nod to the company’s long-standing tradition of serving ...

But most Chicagoans know that Portillo's best-kept secret is its cake shake. Customer: It's a shake and it's Portillo's chocolate cake at once. It's amazing. It's an evil idea. I don't know who ...