On the Laravel News site there's a post sharing a guide (and a screencast) that helps you set up XDebug and Laravel Valet to work with PHPStorm for debugging your code.

I’ve been developing web applications for about 15 years, but somehow Xdebug is still challenging to set up. Follow along and learn how to find Xdebug settings and configure it for local development with PhpStorm.

If you are using PHP-FPM locally, you might have run into an annoying issue that no matter what you do Xdebug won’t work! I might have an answer for you in this video.

The video, viewable either in-page or on YouTube directly. It's about 15 minutes long and provides you with the prerequisites, commands to get everything set up and the configuration changes to make to the PHP config and PHPStorm to get them working together.