4-6 Theobald's Road
I always get excited when I see bánh mì on a menu - these sandwiches are absolutely amazing when they are done right. I pass by this place on my walk to and from work so it made sense one day to pop in and see if they were making bánh mìs to my specifications. The guy behind the counter recommended the Bahn Mi Bay Special, which includes pork pate, pork roll and spiced pork. They also have an option of a special Vietnamese baguette - it costs a bit more but is more authentic as it is made with rice flour rather than wheat.
When I took a bite, I was a little disappointed by the bread-to-filling ratio - the flavors of the filling weren't punchy enough to stand up to all of the bread. I love all of the ingredients that go in, especially the pickled vegetables and cilantro, but for some reason everything tasted a bit muted. That said, it's still a bánh mì and so I still finished it - it just wasn't one that I would necessarily rave about or go back for.