Tender fish fillets and noodles swim in a tangy broth of pickled mustard greens. This Sichuan-inspired family soup is high in protein, fresh, and delivers a satisfying sour kick.
Slice the fish fillets into bite-sized pieces and set aside. Soak the rice noodles in warm water until softened, about 15 minutes, then drain.
Heat 2 tbsp vegetable oil in a large pot over medium heat. Add Sichuan peppercorns and ginger slices, stir until fragrant (about 1 minute), then add minced garlic.
Add chopped pickled mustard greens and sauté over medium-high heat for 2-3 minutes to release flavor, ensuring not to brown the vegetables.
Pour in the chicken broth and bring to a rolling boil. Add soy sauce, rice vinegar, salt, and white pepper; simmer uncovered for 10 minutes to develop the tangy base.
Add fish fillet pieces to the simmering broth. Reduce heat to medium-low, poaching the fish gently for 3 minutes until opaque and just cooked through—avoid stirring vigorously.
Add soaked rice noodles and green onions. Simmer for 2-3 more minutes until noodles are tender but still have a bite. Adjust salt to taste.
Ladle soup into bowls, ensuring equal distribution of fish and noodles. Serve immediately for maximum freshness and ideal texture.