Peel the shrimp, remove the stomach and vein. Marinate the shrimp meat with 1 tablespoon fish sauce. Rinse the shrimp shells and drain. Sauté onion and garlic until fragrant, add the shrimp shells and stir-fry with 1 tablespoon fish sauce. Add 8 1/2 cups water (2 liters), 1 teaspoon salt, and 1/2 tablespoon rock sugar. Grill a piece of ginger, an onion, and a garlic clove, crush them, and add to the pot with the shrimp shells.

Finely chop the shrimp meat and mix with ground pork. Soak the wood ear and shiitake mushrooms until soft, rinse, then blend with an onion and 3 garlic cloves until smooth. Mix with the pork and shrimp, add 1/2 tablespoon fish sauce and 1 teaspoon sugar. Let marinate for 10 minutes.

Cut the tomatoes into wedges. Sauté onion in oil, add the tomatoes and 1 tablespoon fish sauce, and cook until the tomatoes are soft. Add to the shrimp broth. For a more sour taste, you can add dried tamarind, tamarind paste, or fermented rice. Alternatively, squeeze in lime or calamansi when serving. Add the fish cake and season to taste.

Shape the shrimp and pork mixture into small balls and drop them into the simmering broth. When the meatballs float to the surface, briefly blanch the banh da noodles or substitute with pho or rice vermicelli noodles.

Place the blanched noodles in bowls, add the shrimp-pork meatballs and fish cake, then ladle the hot broth over. Top with chopped scallions and Vietnamese coriander. Enjoy!

Note: Do not leave the shrimp-pork meatballs floating in the broth for too long, or they will lose their sweetness.