Homologate Doctor Diploma

When you say you are "a Greek citizen", do you have a Greek passport or ID card (ταυτότητα)? Do you speak Greek?  Without these, you may find it difficult to practise medicine in Greece.

In principle the process to have your qualifications recognised is as follows: you'll need to get your Cuban MD diploma verified by the Cuban Ministry of Higher Education. They will issue an official document confirming the authenticity and validity of your degree.  That verification will have to be apostilled/legalised by the Cuban Ministry of Foreign Affairs. You will then need to take both of those documents to the Greek Consulate in Cuba to have the legalisation by the Cuban Ministry of Foreign Affairs legalised by the Hellenic Ministry of Foreign Affairs.

All of those will have to be sent to DOATAP in Athens to have your qualifications investigated and recognised - more information here: https://www.doatap.gr/home_english/

I stress that this is broadly the process you'll need to go through; the exact details may vary.  You'll probably find it useful to hire an attorney in Athens to handle the process in Greece and to advise you on the correct procedure in your particular case.  Feel free to message me if you'd like a recommendation for a lawyer - it isn't me!   Be warned that Greek bureaucracy works at it own pace, and it's not uncommon for rules and regulations to be interpreted in bizarre ways, or simply made up on the spot...