haven’t been to GBK in ages but i remember them being good.
there’s one here now called Bunsen, the menu is written on a small piece of card cos it’s very simple, there are only a couple of options. they don’t go in for any variety of toppings like bacon or blue cheese or egg or any of that (which i do normally quite like), just standard lettuce and tomato etc and they use that processed cheese like McDonalds (not as good as real cheese obviously but i’m actually fine with this). but MY WORD the meat. they ask how you want it cooked, if you get it medium it’s so so juicy. you really have to order a double to experience the true joy of it as the single doesn’t quite do it justice. the double is a face-full of gorgeous juicy juicy meat. wonderful.