Place a large frying pan / skillet / wok on medium-high heat. Drizzle with 1 tablespoon vegetable oil, then add in your sliced onions. Fry for a couple of minutes, stirring frequently.
Add in the ground pork and break the meat apart with a spatula. Fry for 10 minutes, leave the pork to cook and stir occasionally.
After 10 minutes, or once any excess liquid has evaporated and the pork has started to brown in certain patches, add in the garlic and ginger. Fry for another minute, then add in the carrot, cabbage, and mushrooms. Fry for 2 minutes, then add in the celery.
Pour in the soy sauce, sesame oil, and oyster sauce. Stir fry for 2 minutes, then taste and season with more sauces, salt, and/or pepper. It should be super flavourful with the carrot and celery still slightly crunchy! Then transfer to a large plate and leave to cool in the fridge for 10 minutes.
Once the filling has cooled, get your rice paper wrappers. Grab a large plate or bowl and fill with warm water. Dunk the rice paper wrapper into the water so it's submerged for a couple of seconds, then remove and place onto a clean chopping board. Place 2 tablespoons of the filling 2 inches from the base of the wrapper. Once the wrapper has changed texture to a slightly sticky texture (after 10-20 seconds), pinch the base of the wrapper and fold over the filling. Fold in the sides of the wrapper, keeping the filling firm, then tightly wrap the rice paper into a roll (see images further up this blog for reference).
You then want to wrap that rice paper roll in another wrapper to ensure it doesn't break while air frying. Then set this aside and repeat for all 8 summer rolls.
Place the rice paper rolls into your air fryer (ensure they're not touching), and cook for 10 minutes at 200C / 390F. Keep an eye on the rolls to ensure they don't burn. Then serve up with sweet chilli sauce and enjoy!!