Delicate fish fillets are poached in a tangy pickled mustard green broth for a vibrant Sichuan soup. This high protein, fresh family dish is low calorie and delivers an addictive sour kick.
Slice the fish fillets into thin bite-sized pieces, then scatter with a pinch of salt, white pepper, and the Shaoxing wine. Set aside to marinate for 10 minutes.
Rinse and roughly chop the pickled mustard greens; slice the scallions on a bias. Prepare the garlic, ginger, and chilies before starting so everything is ready.
In a large pot over medium-high heat, add 1 tbsp oil. Sauté ginger and garlic until aromatic, about 30 seconds, keeping heat moderate to avoid browning.
Add Sichuan peppercorns and dried chilies, stir for 15–30 seconds, then immediately add pickled mustard greens and bean sprouts. Sauté 2–3 minutes to release aroma.
Pour in chicken broth and soy sauce, bring to a boil, then lower to a gentle simmer to meld flavors for 8 minutes. Skim off any foam for a clear broth.
Add the fish fillets piece by piece to the broth, ensuring the heat is on a gentle simmer (not a rolling boil) to keep the fish tender. Poach 2–3 minutes until just opaque.
Taste and adjust seasoning with salt and extra white pepper if desired. Ladle soup into bowls, scatter with scallions, and serve immediately for peak tenderness.