Arby's Bronco Berry Sauce Is Unlike Any Other Fast Food Chain Signature Sauce - Chowhound

Summer_Wind/Shutterstock In this day and age, fast food joints are practically required to have a signature sauce to stand out in a crowded field. Chick-fil-A's signature sauce has a mustard and barbecue base. In-N-Out's "spread" is akin to Thousand Island dressing. Shake Shack's signature Shack Sauce goes heavy on the mustard and pickle brine. But for another quick-service sandwich shop (famous for roast beef),…