Quality Bakso should be 'bouncy' (elastic). This is achieved by very fine grinding and the addition of tapioca starch and ice water/ice. It's best to process the meat in a food processor to emulsify the fat and meat, but you can also buy ready-made meatballs in Asian stores.
Place the ground beef, tapioca starch, salt, white pepper, and baking soda into a food processor.
While blending, gradually add the ice water/ice cubes until a very smooth, sticky, and bouncy paste (emulsion) is formed. This should take about 5 minutes.
Bakso balls are traditionally shaped by hand: scoop some meat mixture into your palm, squeeze your fist until the mixture pops up between your thumb and forefinger. Use a spoon to scrape the ball off.
Bring a large pot of water almost to a boil (about 80 °C (176 °F)). The water should not be boiling so the Bakso doesn't overcook.
Drop the shaped meatballs into the hot water. Cook until all the balls float to the surface (about 15 – 20 minutes).
Remove the Bakso balls, drain them, and set aside. You can transfer them to cold water to stop the cooking process.
Heat the beef broth. Add the fried garlic, spring onion roots, white pepper, and season with salt.
Cook the noodles and blanch the vegetables (bok choy).
Place the cooked noodles, tofu, and blanched vegetables into a bowl. Add the Bakso balls and pour the hot broth over everything.
Serve the Bakso soup hot, garnished generously with chopped spring onion, celery leaves, and fried shallots. Each person adds Kecap Manis (sweet soy sauce) and Sambal (chili paste) to taste.