To make it, you soak thin rice noodles in water for a few hours, mix them with tapioca flour, and then steam some using a splatter guard between a pan and its lid for five minutes. They come out a solid mass after that, which can be used in sheet form in spring rolls or cut up into smaller pieces. You wouldn't want to serve someone a whole sheet on a plate, because they're a bit of a pain to cut.
I had just done a lot of cleaning in the house and organizing in the kitchen, so I didn't feel like going out to pick anything up to serve with it. I settled on some bacon Spam which I marinated in lemon juice, soy sauce, Sri Racha, and hoisin for about 40 minutes.
Ideally, this should be served with a better meat, such as charbroiled pork, as well as greens for wrapping and dipping into fish sauce. And not the plain stuff, but the house stuff with vinegar, sugar, and/or whatever else is in it. I could look up a recipe, but don't feel like it since I just ate the meal without it.
So here's what I ended up with:
Banh hoi detail:
The banh hoi is garnished with scallions heated in peanut oil, which is a typical preparation. Half a cucumber, a whole tomato, and some lemon soy sauce accompany.
This was a lot of work and pretty complicated. I'm really happy I can do this and make it with better stuff in the future.