Cut the chicken breast diagonally into thin strips, the onion lengthways into thin strips, the washed spring onions (with greens) into 2 cm pieces, and the dried chilli peppers into 3-4 pieces each.
Heat the rapeseed oil in a wok over high heat.
Add the chicken strips and fry for 1-2 minutes.
Add the onion and stir for 30 seconds, then add the chilli peppers and stir for another 30 seconds.
Sprinkle the sugar on top and stir well.
Mix the soy sauce and water together, then add to the wok and stir.
Add the spring onions and cashew nuts, and stir until the chicken is cooked through (74°C / 165°F internally).