For anyone who has visited Vietnam and tasted even the street food in Saigon, the opportunity to go Vietnamese in Havana would be a treat to be savoured. Unfortunately, Hanoi Havana is just a name and the food is standard Creole fare.
The Hanoi is one of the only fully restored buildings in the untouristy Plaza del Cristo del Buen Viaje, which dates back to 1640 adjacent to the church of the same name, also called “Calvary Chapel” because it used to be the final station for the Via Crucis procession along Amargura Street. I like the church here and there is always a good local atmosphere with local kids playing basketball/volleyball and all of the real noise of a Cuban neighbourhood as opposed to the somewhat forced beautification, which exists in the more touristy areas of Old Havana.
This is a cheap and cheerful place (although possibly not as cheap as it could be); there is a down-at-heel scruffy feel to the place without actually being down at heel. This is the sort of place you will find backpackers looking to discover the real Cuba, of simply have a decent meal on the cheap.