Havana [1] reflects all the horror stories about Cuban dining. Fortunately, it does have some fine restaurants, many in the top-class hotels. The number of private restaurants (paladares) had fallen from 600 to fewer than 40 at last visit.
The four state-run vegetarian restaurants, launched in 2004, also ceased functioning as such.
Some establishments mentioned in this travel guide may close by the time of your visit.
Links:
[1] http://www.moon.com/destinations/cuba/havana