To void an item from an existing table or tab on the Bustle iPad till app
Locate and open the tab on screen
Find the item
Swipe from right to left (like deleting a text)
Press Void (or do a long swipe to complete the void)
Press Close Tab
If you have automatic printing or select to print the docket, it will re-print the original docket displaying the voided item clearly for the chef / barista / preparer.
In this image we have an item in the process of being voided, as well as an already voided item (the Latte) showing strikethrough to indicate it has been voided.