Looks very "Tachinid-ish" and seems to be a male Catharosia pygmaea, though the wing pattern in different from Dutch ones. C.pygmaea is a very variable species.
Great! Thank you!
Well, I thought it was Rhinophoridae because of the wing pattern.
I read a little uncertainty in "seems to be" so maybe there are other options among the Tachinids too ... (?)