In a large bowl, combine the ground beef, beef fat, tapioca flour, minced garlic, salt, white pepper, and baking powder.
Gradually add ice water, mixing until you get a smooth and sticky dough. It should be thick enough to hold together but not too dry.
Shape the mixture into small balls, about 1 inch (2.5 cm) in diameter.
Bring a large pot of water to a boil. Add the meatballs in batches and cook until they float to the surface, about 5-7 minutes. Remove them with a slotted spoon and set aside.
In a separate pot, heat a little oil and sauté the minced garlic until fragrant.
Add the beef or chicken broth, soy sauce, salt, and white pepper. Bring to a simmer.
Add the cooked meatballs to the broth and simmer for about 10 minutes.
Stir in the bean sprouts and green onions, cooking for an additional 2 minutes.
Place a portion of cooked noodles in each serving bowl.
Ladle the meatball soup over the noodles.
Garnish with fried shallots (if using), chopped cilantro, and sliced chilies or sambal.
Enjoy your meal!