
Peel the shrimp and set the shrimp heads and shells aside. Devein and if the shrimp is medium or large, split in half horizontally.
Place a pot over medium heat and once it is hot, add oil to lightly coat the bottom. Add the shrimp shells and heads. Sauté until they are browned and smell flavorful, then add the water and 2 teaspoons salt.
Bring the pot to a boil, then lower the heat to maintain a gentle simmer. Cover and simmer for 45-60 minutes (or longer for stronger flavor). We will cook the toppings during the simmering time.
Soak dried wood-ear mushrooms in hot water to reconstitute them. After they have been rehydrated, chop off the stems, then julienne. You will have about ¾ - 1 cup of julienned mushrooms.
Place a skillet over medium heat. Lightly coat with oil and once it is hot, add 2 teaspoons minced shallot. Sauté until fragrant and add the shrimp. Stir and cook for a minute, then add 1 teaspoon fish sauce, black pepper and ¼ teaspoon salt (to taste). Cook for another minute or until the shrimp is cooked through and has absorbed the flavors. Transfer to a clean plate.
Add some more oil to the same skillet if needed. Then sauté 1 tablespoon minced shallot until fragrant. Add the julienned mushrooms and 2 tablespoons water. Stir and cook briefly, then season with 1½ teaspoons fish sauce and black pepper. Cook for 2-3 more minutes, then transfer to a clean plate.
Add some more oil to the same skillet if needed. Then sauté the remaining minced shallot until fragrant. Add the minced garlic and also sauté until fragrant. Add the pork and increase the heat if needed. Cook until the outside is still slightly pink, and add ½ teaspoon fish sauce, black pepper and the remaining salt (to taste). Continue to stir-fry and after the pork is fully cooked, transfer to a clean plate.
Lightly coat the same skillet with some more oil if needed. Add the tomatoes. Stir and cook until the outside starts to soften. Set aside until the shrimp stock is ready.
Once the shrimp stock is ready, discard the shrimp heads and shells. Transfer the tomatoes from the skillet to the stock pot. Simmer for about 5 more minutes to let the flavors meld. Season the broth with the remaining fish sauce and adjust to taste.
Place prepared vermicelli noodles into serving bowls. Divide the shrimp, wood-ear mushrooms and pork slices among them. Top each bowl with chopped dill, scallion and cilantro.
Ladle the broth into serving bowls. Serve right away.