How to get ViewComponent as string in the controller?

I've searched around on how to get a ViewComponent as a string.

I found the method to do it in .cshtml razor like this:

var writer = new System.IO.StringWriter(new System.Text.StringBuilder());
(await Component.InvokeAsync(typeof(MyViewComp))).WriteTo(writer, HtmlEncoder.Default);
string viewCompString = writer.ToString();

But i cant do this in the backend, because the Component object is derived from razor that you can get in .cshtml, but not in the controller (i think).

Any help appreciated! :)