Fold rather than cut, stops the filling from splurging out.
Dear God!
If you can fold it, you haven’t got anywhere near enough in it!
Cut a sandwich in half? Do you people have small hands or something?
No, just very well-filled sandwiches. The only reason not to keep a sandwich whole is if it’s got a still-runny fried egg and/or baked beans (or chilli con carne or similar) in it, because if you cut those you end up with most of it failing to stay within the bread.