Got a tasty and pretty authentic banh mi in Marina Bay of all places today....new place called Gaveston has taken over the Marina Bay market. I was told that the chef is from Vietnam.
There is no signage yet, so it was a little tricky to find. They also have pho and vermicelli and some regular sandwiches like turkey club, etc.
The Banh mi was pricey at $7 each but very tasty. We ordered barbecued beef but it wasn't grilled teriyaki beef like at Pho Viet, but a piece of beef similar to bresole...almost a cured meat. It came with pate, some type of ham loaf, the usual carrot, cilantro, etc. We got it with hot pepper and it came with tiny fiery red bird chilis...
Since Saigon Kitchen in North Quincy has stopped making Banh mi, this is a good alternative. Just wish the price wasn't so high!