I saw this on WP Tavern and noting it here for the future.
With Gutenberg you can make reusable blocks. The neat thing about them is that if you subsequently edit the block, you change it for every appearance on the site. That can be handy if you need to update some information contained in the block.
The tip on WP Tavern was that if you want to see the reusable blocks you have made, log in to the admin panel and then add the query and you will see them listed.