Take your batter out from the fridge and stir to reincorporate the batter.
Right before you begin making your banh xeo, add the minced green onions to your batter.
Before you start, make sure you have all your components ready. This would be your batter and fillings.
Add onions and shrimp to a nonstick pan that is 8 inches in diameter. Saute for 1 minute over medium heat until the shrimp turns slightly orange. Add in a few pork pieces.
Add 1 tablespoon of oil to the pan. Make sure the pan and oil are hot before adding in your batter.
Use a ladle to spoon in your batter. As you ladle in your batter, tip your pan in a circular motion so that the batter spreads in a thin layer throughout the pan. You should use a little less than 1/4 cup of batter each time. Add in 1 teaspoon of the mung bean and a small handful of bean sprouts. Cover and let cook for ~3 minutes until the banh xeo has cooked through and the outside is crispy.
Once the batter has cooked through, fold it in half.
Repeat process until your batter and/or filling is finished. After every 2 banh xeo you make, use a paper towel to clean the pan.