Heat a large wok or non-stick pan over medium-high heat.
Add a few tablespoons of oil.
Wait a few seconds for the oil to heat up.
Sear the beef in batches until they are browned. They do not need to be fully cooked through at this stage.
Set the beef aside on a large plate or bowl.
Add more oil to the pan if needed.
Add the onions, garlic, celery and asparagus.
Toss everything together and cook for a few minutes until the vegetables start to soften.
Add the prepared noodles, together with all of the sauce.
Give everything a good mix and make sure all of the noodles are coated in the sauce.
As everything starts to simmer and the sauce thickens, add more hot water as needed to create a thick sauce or gravy. Keep tossing the noodles to ensure that they are evenly cooked.
Return the beef to the pan and stir through the noodles.
If you like extra spice, mix through the red chillies just before serving.
Serve immediately.