On the way back to our hotel, we made a quick stop at a bánh mì shop that was recommended to us (82 Nguyễn Thiện Thuật, 833-4288). I liked these guys better than Bánh Mì Như Lan, as the sandwich had an interesting taste of coconut butter or something.
The bread was a bit softer than I was expecting (perhaps because it sat for a while before we ate it?), but it worked. I also spotted one of those rotating kebab spit contraptions out front - presumably as roasted meat to go into a sandwich, which would definitely be worth trying next time.