The banh mi burger is a very tasty emerging trend. Most of the banh mi burgers I have heard about are created by American restaurants and burger joints rather than Vietnamese banh mi shops. Rub BBQ in NYC has one as a sometimes special and another place in Redhook Brooklyn offers them too. The Houston version I tried was pretty impressive.
It was called a “Saigon burger” at The Burger Guys on Westheimer near Kirkwood and it featured their standard half-pound akaushi burger patty on a toasted hamburger roll spread with French-style paté and topped with pickled carrot and daikon–extra jalapeños on request. I would love to sample a banh mi burger made on a banh mi baguette. If you see one in Texas, let me know.
The original banh mi sandwich is a syncretized Viet-French creation, but I am thinking the American-born Vietnamese burger is an example of full-on creolization. Especially if the pickled jalapeños come out of a Mexican La Costeña can.