Using a sharp knife, finely chop and mince the ground meat to smaller pieces. The Woks of Life has some great tips to grind your own meat if you don't have a grinder; I've attached the link to her website below. Or get a butcher to grind the meat for you.
In a bowl, combine the ground pork with all the other ingredients (except napa cabbage). Using a spatula or your hands, stir the mixture with a firm hand, whipping in one direction for 10 minutes until it resembles a paste. Pick up the meat and "slap" it back into the bowl to create an elastic texture. You'll need to achieve this consistency so the meat doesn't fall apart when it goes into the boiling pot of soup.
Prepare your pot of prawn/chicken stock. Once it starts boiling, turn down fire to low and simmer until thoroughly heated. Add garlic then season with salt and pepper.
Gently break one egg into a big soup ladle, then slowly lower the ladle into the simmering stock to poach. Once poached, transfer to a bowl. Repeat with the other eggs.
Add prawns and napa cabbage into the stock and blanch for 3 minutes. Remove and transfer to a bowl.
Coat your hands with a few drops of oil, then divide the meatball mixture into 8 or 9 equal portions and shape each into a ball. Carefully drop them into the simmering stock. Cook them in batches. Once they are cooked and float to the top, remove them with a slotted spoon.
Finally, add the cornstarch slurry to the soup and stir well until the stock thickens.
Place crispy yee mee in a bowl or deep plate. Add prawns, meatballs and napa cabbage, then top it with poached eggs and spring onions. Finally pour the hot broth over the noodles. Serve immediately with sliced bird's eye chillies mixed with soy sauce.