Dan bing is a traditional Taiwanese breakfast food that is usually sold by street vendors every morning. Since everyone is in a rush to get to work (sometimes waiting with their scooters running), the vendors have to be able to make every order to go super fast, and once you get the hang of it, you can make it pretty quickly at home, too!
Basically, a dan bing is a thin crepe with an egg on top. There's multiple variations; my favorite is just to mix a little sesame oil and a lot of chopped scallions into the egg. Feel free to try different fillings in the egg mixture (e.g. chopped ham, crumbled bacon, corn) or on top of the cooked egg before rolling it up (e.g. shredded cheese, rou song [pork floss], cilantro), but I wouldn't put too much in because you want to make sure you can still roll it up easily. Soy paste and sweet chili sauce are the more traditional sauces, but you can also try oyster sauce, hoisin sauce, or even ketchup.
It is usually sliced into bite-sized pieces (similar to a makil roll) if you're going to eat it sitting down, but you can eat this on the go by spreading the sauce on the egg before you roll it up and eating it like a wrap or burrito. —Joy Huang | The Cooking of Joy
Mix the bread flour and corn starch together in a small mixing bowl. Add the water and a pinch of salt and mix well. Let the batter rest for about 10 minutes while you assemble the rest of the ingredients.
For each crepe, beat 1 egg with 1/4 teaspoon of sesame oil, 1 tablespoon of water, a pinch of salt, and a heaping tablespoon of chopped scallions.
Start heating a non-stick pan on medium heat and lightly oil. Once the pan is hot, stir the batter again (it may have separated slightly) and add a third of the batter (about 1/2 cup) to the pan. Swirl the pan around to coat the bottom with a thin layer. Cook the crepe until the top is set and the edges pull easily away from the pan. Flip the crepe onto a plate and slide the crepe back onto the pan, cooked side up.
Pour the egg mixture on top of the crepe, and carefully spread it out with a spatula. Try not to have any of the egg go over the edge of the crepe if possible.
Continue cooking until the egg is mostly set and then flip (the crepe will be sturdy enough to flip with a spatula now). Cook for 10-20 seconds and then flip the crepe egg side up onto a plate or cutting board.
Quickly roll the crepe into a long, rectangular roll. Cut into sections and serve hot with soy paste and/or sweet chili sauce.