The greatest tacos ever to grace a greasy shell in DFW are almost always found inside an unsuspecting gas station. This is Texan knowledge 101. It goes in the same handbook that requires Texans to love anything dealing with longhorns, brews, queso, margaritas and recently, Topo Chico. By the Horns Brewing has not only read this handbook, they’ve turned it into doctrine. Located in Mansfield, By the Horns Brewing is the latest brainchild of Chef Jason Boso. He’s the man behind the comfort food classic concepts, Twisted Root Burger, (there’s also one next door) and the forever bustling Truck Yard. Some who’ve spent a little time chasing cheesesteaks and…