Prep all your ingredients.
In a pot, boil the water on medium high.
Add the onions, salt, sugar and pepper. Let it simmer on medium low.
In a large bowl, add the pork mince, fish sauce and pepper. Use your hands to combine thoroughly. Put a small piece of meat onto a plate and in the microwave for 30 seconds or until cooked. Taste check for the seasoning and adjust to your liking.
Use your hands to mould into meatballs. Add the meatballs to the soup and cook until all the meatballs are floating.
Add the sliced zucchini and turn the heat up onto medium high. Once the water starts boiling, turn the heat off and put the lid on. Let it sit for 2 -3 minutes.
Check the zucchini to see if is cooked. If no, then turn the heat back on until done to your liking.
Add the fish sauce, then check the soup for seasoning / flavour. Adjust to your taste. (Please refer to the tips section above for advice.)
Garnish with spring onions, and serve with rice or by itself.