How open an existing Workspace containing projects

This is a rather old topic, but it could still be informative. How ever; when I search on “How open an exiting Workspace in PlatformIO/VSCode” I don’t find what I, looking for.
What I do find is this:
pfeerick says:
“Workspace - VSCode allows you have multiple projects within the one workspace, which can be saved and re-opened later.”

Quite nice, that’s exactly what I have, but…
How do I open that existing Workspace with all my projects and their dependencies in it?