Photo by jing-a-ling The quality of a jumbo slice is something that most Washingtonians know is best left to be pondered after a night of heavy boozing. So we’re a little surprised that the Travel Channel show Food Wars is pitting two local purveyors, Pizza Mart and Jumbo Slice, against each other to see who serves it up best. Less surprising is the wealth of man-on-the-street interviews included, featuring some of our city’s finest…