Using ApprovalTests in PowerShell

PowerShell has the Pester framework to allow automated testing. It includes many useful testing features but does not bring ApprovalTests.NET like functionality out of the box, specifically: using example files to verify expected results.

What is the recommended way to write ApprovalTests.NET like tests in PowerShell (with or without Pester/ApprovalTests.NET)?

My goal is to reduce verbose hard-coded expectations in PowerShell files.