1-First Step: Prep the broth ingredients Start by washing, peeling, and cutting the daikon and jicama into large chunks. Rinse the dried squid and dehydrated scallops lightly, then set them aside. If your crab is whole, clean it well and break it into pieces so it can give the broth more flavor. In a large stockpot, add 10 liters of water, the daikon, jicama, dried squid, dehydrated scallops, pork hock, and crab. Bring the pot to a boil over high heat, then lower to a steady simmer. Skim off any foam that rises, because this keeps the broth clear and clean-tasting.

2-Second Step: Build the broth flavor Once the pot is simmering, stir in the rock sugar, salt, fish sauce, and chicken bouillon powder. Add the annatto seeds to 1 tablespoon of oil in a small pan and warm them gently until the oil turns a deep orange-red. Pour the annatto oil into the broth for that classic reddish color and rich aroma. Let the broth simmer for about 1 to 1 1/2 hours. This slow cooking time helps the pork hock become tender and gives the seafood time to release its flavor. If the liquid drops too much, add a little more water so the soup stays generous.

3-Third Step: Make the slurry and thicken the soup Mix 1/2 US cup potato starch with 1/4 US cup water until smooth. Stir the slurry into the broth little by little while the soup is gently bubbling. Keep stirring so the broth thickens evenly and does not clump. You want the texture to be silky and lightly thick, not heavy. If the soup gets too thick, add a splash of hot water. If it still feels thin, add a little more slurry, but go slowly because it thickens as it cooks.

4-Fourth Step: Prepare the prawn balls Heat 1 tablespoon oil in a pan and fry the chopped shallot, garlic, and spring onion until fragrant. In a bowl, chop or pulse the peeled prawns until sticky, then mix in the fried aromatics, salt, sugar, chicken bouillon powder, pepper, and fish sauce. Shape the mixture into small balls. Fry the prawn balls in cooking oil until they are golden and cooked through. If you want a lighter version, you can also poach them in the broth at the end instead of frying. That keeps the soup a bit lighter while still giving you plenty of flavor.

5-Fifth Step: Cook the noodles Boil the Banh Canh tapioca noodles according to the package directions or until chewy and tender. Drain them well and rinse only if the package suggests it. If you are serving right away, toss the noodles lightly with a bit of oil so they do not stick together.

6-Sixth Step: Assemble the bowls Place the noodles in each bowl, then top with crab meat, slices of pork hock, prawn balls, and blood jelly if you are using it. Ladle the hot broth over everything so the noodles soften a little more and soak up the broth. Finish with chopped coriander, spring onion, fried onions, black pepper, and a squeeze of lime juice. Serve the soup hot with extra lime on the side so everyone can adjust the brightness to taste.

7-Seventh Step: Taste and adjust Before serving, taste the broth one more time. Add a bit more fish sauce if you want more savoriness, a touch more sugar if you want a softer edge, or more lime juice if you like it brighter. This final check makes the bowl taste balanced and fresh.