Sichuan Numbing Sour Fish (Suan Tang Yu)

Ingredients

• 800 g snakehead fish (li yu) or grass carp, whole fish cleaned, or thick fillets
• For the sour broth
• 2 tbsp Pixian doubanjiang, light measure — not the dominant flavour
• 200 g suan cai (pickled mustard greens), rinsed, roughly chopped
• 2 medium tomatoes, ripe, cut into wedges
• 1 litre fish stock, light, unsalted or lightly salted
• 15 g fresh ginger, peeled, sliced
• 3 spring onions, white and green parts, cut into sections
• 2 tbsp neutral oil
• To finish
• 2 tbsp chili oil
• 1 tbsp Sichuan pepper oil
• 100 g glass noodles, soaked until pliable, optional; added in the last 2 minutes

Method

1. 1
   Heat the oil in a wok or wide pot over medium heat. Add the doubanjiang and stir-fry for 1–2 minutes until the oil turns a deep brick-red and the paste smells fragrant and toasted. Add the ginger and the white parts of the spring onion and stir for a further 30 seconds.
2. 2
   Add the suan cai and tomato wedges. Stir and press the tomatoes lightly so they begin to break down. Cook for 3–4 minutes until the tomatoes have softened and the base smells sharply sour. Pour in the fish stock and bring to a gentle simmer. Taste: the broth must be assertively sour at this stage; if it is not, add more suan cai. This is where the dish lives or dies — insufficient acid from the pickled vegetables and tomato will render every subsequent step irrelevant.
3. 3
   Lay the fish — whole or in thick fillets — into the broth while it is still cold or just warm. Raise the heat gently and allow the broth and fish to come to temperature together. The fish is done when the flesh turns opaque throughout and yields to the lightest pressure without resistance. Do not boil aggressively.
4. 4
   If using glass noodles, add them in the final 2 minutes of cooking. They are ready when translucent and supple, having absorbed the sour broth.
5. 5
   Transfer the fish and broth to a serving bowl. Drizzle the chili oil and Sichuan pepper oil over the surface. Scatter the green spring onion tops. The surface should carry a thin slick of red-orange oil with a faint numbing aroma rising from the bowl.