Toss the chicken pieces in the cornflour and season well. Set them aside.
2
Fry the onion in half of the oil in a frying pan or wok on a low to medium heat, until it softens – about 5-6 minutes. Then add the garlic and cook for a minute. Stir in the spices and sugar and cook for another minute, then add the stock and soy sauce, bring to a simmer and cook for 20 minutes. Tip everything into a blender and blitz until smooth.
3
Wipe out the pan and fry the chicken in the remaining oil until it is browned all over. Add the mushrooms and fry for a couple of minutes. Tip the sauce back into the pan and bring everything to a simmer, stir in the peas and cook for 5 minutes or until the chicken is cooked through. Add a little water if you need to thin the sauce.