Clean the pork hock, then place it in a pressure cooker with a pinch of salt and cook for about 15 minutes. Chop garlic and shallots, sauté them in a pot until fragrant, then add the pork hock broth along with 4 cups (1 liter) of water. When the broth comes to a boil, sauté a little annatto seed oil and add it to the broth for color.

Add the strained crab meat. When the crab rises to the surface, gently skim it off and set aside. Next, add the shrimp; when they float to the top, remove them. Season the broth, adding 1 teaspoon fermented shrimp paste for extra flavor. The broth is now ready. Prepare lime and chili slices.

Place the blanched bánh canh noodles in a bowl, arrange the pork hock, crab, and shrimp on top, ladle the hot broth over, and garnish with green onions, cilantro, black pepper, and fried shallots.