Sending headers in when starting a workflow from the CLI

The workflows that we have built at our company pass in a tenant identifier as a header or context across our workflows. I am trying to start the workflow from the CLI just to test it locally, but everything fails because i cant get the tenant id into the header of the workflow.

I saw the grpc-meta flag on the docs Temporal CLI command options reference | Temporal Documentation
But i cant figure out how to get that to work and there are no examples anywhere of anyone using it.

Basically has anyone used it and could give me some pointers on what to do.