A store that is open on the Sabbath can sell glatt kosher meat. The meat will still be just as kosher. What to me is very misleading about delis is that sometimes they say they are kosher style but not really kosher. A restaurant that serves Glatt Kosher prepared food must be closed on sabbath. Simply for the fact that Glatt meat(all kosher meat) has to be slaughter by a Jew but glatt has to have closer supervision. Also the food is only kosher if a jew turns ont he oven. I think I am right. I went to a really religous yeshiva high school and we learned the talmud that discusses just matters like this.