1-First Step: Clean and blanch the pork bones Start by rinsing the 3 pounds of pork bones well with cold water. Rub them with 1 teaspoon of salt for cleaning, then rinse again. This helps remove any cloudy bits and gives you a cleaner broth. Place the bones in a large pot, cover with water, and bring it to a boil for a few minutes. Drain, rinse the bones one more time, and wipe out the pot if needed.

2-Second Step: Build the broth Add the cleaned bones back to the pot along with 3 quarts water, 1 large yellow onion or 4 shallots, and 1 small daikon peeled and cut into chunks. Bring everything up to a boil, then lower the heat to a gentle simmer. Skim off any foam that rises to the top during the first 20 to 30 minutes. After that, stir in 2 tablespoons stock bouillon powder, 1 tablespoon sugar, 1 tablespoon salt, 1 teaspoon MSG, and 1 tablespoon fish sauce. Let the broth simmer for about 1 1/2 to 2 hours so the pork bones can release flavor into the soup.

3-Third Step: Add color and thicken the broth If you want a richer color, stir in a little optional annatto oil or food coloring. Some cooks love that warm orange-golden look because it makes the soup feel extra inviting. Next, mix 1/4 cup tapioca starch with 1/2 cup cold water to make a slurry. Slowly pour it into the simmering broth while stirring. The broth should thicken slightly, just enough to coat the noodles later without becoming gluey. Let it simmer for another 5 to 10 minutes after adding the slurry so the starch cooks fully and the texture turns silky.

4-Fourth Step: Prepare the noodles and seafood Cook the 2 pounds Banh Canh noodles according to the package directions. Once they are tender, drain them and toss with 1/2 teaspoon sesame seed oil so they do not stick together. Keep them ready while you finish the soup. In a small pan, heat 1 tablespoon annatto or neutral oil. Add 1 teaspoon minced garlic and cook just until fragrant, about 20 to 30 seconds. Stir in the 1 pound cooked crab meat and warm it gently. Do not cook it too long, or the crab can turn dry. Add the 15 cooked shrimp just long enough to heat through.

5-Fifth Step: Taste and adjust the broth Before assembling the bowls, taste the broth carefully. If it needs more salt, add a little at a time. If it tastes flat, a splash more fish sauce can help. If the broth feels too thick, add a little hot water. If it feels too thin, let it simmer for a few more minutes uncovered.

6-Final Step: Assemble and serve Divide the noodles into serving bowls. Ladle the hot broth over the noodles, then top with the warmed crab and shrimp. Finish with black pepper, 2 scallions sliced thinly, a small bunch of cilantro sliced thinly, fried shallots, and 1 lime cut into wedges on the side. Serve right away while the broth is hot and the noodles still have that chewy bite. If you like a little heat, add chili oil or sliced fresh chilies at the table. That final squeeze of lime brings the whole bowl to life.