The legendary Jambo Texan sandwich was one of the highlights of our BBQ tour. (Photo ©Chris Wilkins) On the way to Lazy S&M BBQ in Joshua, the second stop of our recent South of DFW Tour, we crossed the Chisholm Trail Parkway. The 27-mile toll road, which runs from Fort Worth to Cleburne, is scheduled to open later this year. It was an interesting moment of synchronicity. Our modern barbecue trail intersected -- symbolically anyway -- part of the historic route that Texas cowboys used a century and a half ago to drive their cattle to the railroads. Some might…