Mala crayfish

Step 1: Tip 3 ⅓ lb live crayfish into a sink of cold water and leave for 10 minutes to let grit out. Throw away any that don't move when touched: dead crayfish spoil quickly and aren't safe to cook.

Step 2: Scrub each one with a small brush, especially the underside. Pull out the central fin of the tail with a twist, drawing the dark vein out with it, then rinse well. If you are using prawns, slit the backs through the shell with scissors and pull out the vein.

Step 3: Bring a large pan of water to the boil, drop in the crayfish and blanch for 1 minute, until they just turn red. Drain. (Skip this for prawns.)

Step 4: Heat 5 tbsp neutral oil in a large wok or casserole over a medium-low heat. Fry 3 tbsp Sichuan chilli bean paste (doubanjiang) for 1 minute, until the oil turns red, then add 10 cloves garlic, 1 oz fresh ginger and 4 spring onions and stir for 1 minute.

Step 5: Add 30 dried red chillies, 2 tbsp Sichuan peppercorns, 2 star anise, 1 cinnamon stick or cassia bark and 3 bay leaves and stir for 1 minute, until fragrant but not dark.

Step 6: Turn the heat up to high, add the crayfish and toss for 2 minutes so every shell is coated in the red oil.

Step 7: Pour in 1 ½ cups lager beer, add 1 tbsp light soy sauce and 1 tbsp sugar, bring to the boil, then cover and simmer over a medium heat for 6–8 minutes, stirring halfway. The shells should be bright red and the tail meat white and opaque all through; prawns need only 3–4 minutes, until pink and firm. Discard any crayfish whose tail stays straight after cooking.

Step 8: Uncover, turn up the heat and let the sauce bubble for 2–3 minutes, until slightly reduced and clinging to the shells. Taste and add ½ tsp salt as needed.

Step 9: Pile into a big bowl, scatter with 1 handful coriander and 1 tbsp toasted sesame seeds if you like, and serve with gloves and a bowl for the shells.