Crispy stuffed chicken wings

Method

1. Weigh the chicken wings. Work out 1% of that weight, then sprinkle them with that amount of salt in grams (500g wings would need 5g salt). Set aside in the fridge for 2 hours.
2. Meanwhile, make a chicken mousse. Put the chopped chicken breast, egg and ½ tsp salt in a small food processor and whizz to a smooth, shiny paste (you’ll need to scrape down the sides a few times) [A]. Transfer to a bowl set over ice, then gently stir in the cream. Cover and keep in the fridge.
3. Add a dash of oil to a pan over a medium heat. Once hot, add the mushrooms and fry until their liquid evaporates and they start to turn golden. Add a splash of sherry vinegar and scrape up any burnt bits from the base, then transfer it all to a small food processor and whizz to a paste, seasoning with a pinch of salt and a little truffle oil, if using. Cool, then mix into the chicken mousse with the herbs and zest. Put in a piping bag and chill until needed.
4. After the wings have been salted for 2 hours, put them in a large steamer [B] set over water simmering at around 90°C; use a thermometer to keep an eye on the temperature. Steam the wings for 30-45 minutes, depending on size, then cool for 10 minutes. Use your fingers to carefully slit the skin and prise apart the meat on the smooth side of the flat to remove the bones, one by one (they should slip out easily), trying not to tear too much meat or skin. You want the skin to end up like a pocket with the wing meat inside. Trim away any remaining cartilage, then cool in the fridge.
5. Take a wing and use your fingers to gently open the boneless part. Pipe the mousse into the cavity [C], being careful not to overstuff it (the meat/skin should close back up around the mousse). Repeat until all the chicken wings are stuffed.
6. To make the sichuan chicken salt, toast the peppercorns and cumin in a dry pan until fragrant, then combine with the remaining ingredients in a spice grinder, mortar or blender and whizz/ grind to a powder. Set aside.
7. To make the batter, mix together all the dry ingredients, then pour in two thirds of the water and whisk until smooth [D]. Whisk in the remaining water and set aside.
8. Heat a deep-fat fryer or deep pan two thirds full of oil to 180°C. Add more flour to a plate or container and, in batches, dredge the wings [E], dusting off any excess. Coat the wings in batter [F], then gently lower into the hot oil. Cook for about 5 minutes until golden and crisp [G]. Lift out, drain on kitchen paper, then season well with the sichuan chicken salt.