Heat oven to 200C/180C fan/gas 6. Cook the chicken following pack instructions.
Meanwhile, to make the katsu sauce, heat the oil in a medium saucepan and fry the onion and carrots for around 8–10 mins or until soft, but not golden. Transfer the onion and carrot to a blender. Add the gravy, curry powder, peanut butter and soy sauce, then whizz until very smooth. Pour the sauce mixture back into the pan and heat until simmering hot, stirring frequently.
Slice the chicken into strips, divide between 4 plates, then pour the katsu sauce over. Add a spoonful of pickled red cabbage to each portion and serve with cooked rice and salad leaves.