Heston chicken stock

Directions

1. 1
   One way to boost the deep meaty flavours is to add milk powder to the chicken wings before cooking them. It may sound strange but the milk powder really boosts the Maillard reaction, which is what happens when the proteins and sugars in meat react to being roasted. The resulting stock tastes like the essence of pure roast chicken and you'll never look at a stock cube again!Preheat the oven to 200C.
2. 2
   Put the chicken wings into a roasting tray and sprinkle the top with the skimmed milk powder.
3. 3
   Place in the preheated oven for 1 hour, turning the wings every 20 minutes to ensure they are golden brown all over.
4. 4
   Pour away the fat from the tray and set the wings aside.
5. 5
   Add a little water to the tray, scrape all of the bits from the bottom of the pan and reserve the liquid.
6. 6
   Heat a thin layer of oil in the bottom of a pressure cooker over a high heat. When the oil is hot, add the onion and cook until golden brown and caramelized, stirring frequently to prevent the onions from catching on the bottom of the pan (approximately 45 minutes).
7. 7
   Add the carrot and continue to cook until they are soft and caramelised (approximately 20 minutes) before adding the mushroom and garlic. Cook until the mushroom is soft and cooked through (approximately 10 minutes).
8. 8
   Add the roasted chicken wings and the deglazing liquid as well as the reserved carcass. Cover with 2 litres of water and bring to a simmer, skimming off any impurities that rise to the top.
9. 9
   Place the lid on the pressure cooker and bring up to full pressure over a high heat. Reduce the heat to low and cook for 2 hours.Take the pressure cooker off the heat and leave to cool completely before removing the lid. Strain the liquid through a sieve lined with two layers of wet muslin into another pan, and place the pan in a sink or bowl of iced water to chill it as quickly as possible. Refrigerate overnight and scrape the layer of fat from the surface before using.