LTS of this simple FSP
The middle transition fertig is the shared action so this must be ran parallel, but after this there are 2 transitions which dont have to run parallel, one is kochen and the other is essen. 

Assume, we are now in the point where fertig is done by both processes and now we have 2 options, kochen and essen. We do both one after another as options: if i do kochen then the option essen is left, if i do essen, then kochen is left. I also have to do what is left to do. 

So, let's say, I choose essen then go to USER back, but if I do kochen first, then I have to do essen which is the second essen in this case.