Peel and Devein the Shrimp: Peel and devein the shrimp. Separate half of them and smash them to release more shrimp flavor into the broth. Leave aside.
Prep: Cut tomatoes into wedges, mushrooms in halves, and finely chop green onions and cilantro for garnish.
Marinate Pork: Combine ground pork with green onion whites, 1 tsp chicken bouillon, 1 tbsp fish sauce, and ½ tsp black pepper.
Sear the Pork and Tomatoes & Build the Broth: Sear pork and aromatics in a pot. Add tomatoes and cook until soft. Add water, seasonings, and rock sugar. Simmer, skimming the top to keep it clear.
Sear Shrimp: Quickly sear shrimp with aromatics and annatto oil in a separate pan for 1–2 minutes. Add to the broth 5 minutes before serving.
Cook Noodles & Assemble: Boil noodles, rinse in cold water, and drain. Assemble in bowls with lettuce, noodles, broth, and fresh garnishes.