I remember something else that Kraft may have also made - a blue cheese dip that also had the term ‘Roka’ in its name, and came in a dark blue, fluted metal tin. This was a refrigerated item, and was probably my first introduction to the taste of blue cheese. I don’t think I’ve seen it since the 1960s.
I just looked up a recipe to make Feta Cheese. Doesn't sound too tricky.