The best way to accomplish the recoverability testing of backup files for gold tier virtual machines to meet the customer's requirements is to create a virtual lab in the customer's environment, and then use SureBackup jobs to verify backups. A virtual lab is an isolated environment where you can run your backups or replicas without affecting the production environment. A SureBackup job is a process that allows you to automatically verify the recoverability of your backups by running them in a virtual lab. By using these features, you can ensure that your backups are consistent, functional, and compliant with SLAs and regulations.