The Files->Undelete menu item is used to access the DELETE directory. The directory is read into the active Files window in a easy to use form. Those files that are undeletable are shown with the full pathname. To undelete a file when displaying the DELETE directory, just RMB to access the Undelete context menu, and after selecting the file(s) to undelete, select Undelete from the menu.
Accelerator Keys - Alt Ctrl U