For Greek Orthodox Christians, fasting is a tradition. This usually means eating vegan four to five days a week and being able to eat whatever you want the remaining days. Depending on the region, the fasting rules differ slightly. For example, crustaceans are allowed in Greece, while they are not allowed in Lebanon. Here is for example the Fasting Calendar of the Greek Orthodox Archdiocese of America.
A few ideas about Greek Orthodox Lenten dishes can be found via these two links: