How to include a summary with the recent comments widget?

The current ‘recent comments’ widget only seems to display the name of the user making the comment and the title of the post they are commenting on. I would like to be able to display a summary of their comment as well. With earlier WP versions, I remember being able to include a summary of the comment, but that doesn’t seem to be a clear option.

How can I modify the code to also display a summary of the comment in my recent comments widget?