Translation:This sandwich is familiar in France.
this sandwich is typical in France (would this work too? I guess it should)
"Typical' is a good synonym but it would require a change of sentence pattern. "This sandwich is a typical French sandwich." which would require the learner to use unfamiliar sentence patterns. Thank you and please continue to send in your comments. They are helpful and appreciated.
I think "οικείο" might be better translated to "native" in this context.
I think the better sentence in english would be ' This sandwich is common in France ' opposed to familiar. It sounds less strange to me