LEMP stack downloading php files

I'm working on doing a secure Drupal install on a LEMP stack and am getting php files, info.php or index.php downloading instead of displaying. I see no errors in the logs at all. php-fpm seems to be running ok. I've looked over several discussion groups and it seems to be a common issue when first configuring nginx on a linux box, with MySql (MariaDB) and PHP. I've tried this on an Ubuntu build and a CentOS. I've gotten the server setup to the point of installing drupal and the php processor is failing.

Everyone also seems to think, oh it's just a tweak to the default.conf file/nginx config.
so far I've tried at least a dozen different suggestions and nothing seems to get php files to display properly.

Does anyone know of a link to a tried and true set of tweaks or config suggestions?

Thanks,