Heat the oil in a pan over medium heat. Add the diced onion and grated apple. Cook for 8–10 minutes until soft and lightly golden.

Add the garlic and ginger, stirring for 1–2 minutes until fragrant.

Sprinkle in the flour and curry powder, stirring constantly for 1–2 minutes.

Gradually add the water, stirring continuously to avoid lumps.

Use a hand blender to blend the sauce until completely smooth.

Add light soy sauce, dark soy sauce, Worcestershire sauce, tomato purée, sugar, and salt. Simmer gently for 2–3 minutes until slightly thickened.

Place each chicken thigh between two sheets of baking paper and gently flatten to about 1cm thickness using a rolling pin.

Season both sides with salt and pepper.

Prepare three bowls:

flour in the first

beaten eggs in the second

panko breadcrumbs in the third

Coat each chicken thigh in flour, then egg, then panko breadcrumbs.

Heat about 1½ inches of oil in a deep frying pan or wok to 175°C.

Fry each chicken piece for 4–5 minutes per side until golden brown and cooked through.

Remove and drain on kitchen paper.

Spoon steamed rice onto each plate.

Slice the chicken katsu thinly.

Spoon hot curry sauce beside or over the rice.

Arrange sliced chicken on top and serve with pickled radish or pickled ginger if using.