Pound the chicken to even thickness and season both sides with salt and black pepper.
Set up three shallow bowls with flour, beaten eggs, and panko breadcrumbs.
Dredge chicken in flour, then dip into eggs, and coat thoroughly with panko, pressing gently to adhere.
Heat vegetable oil in a deep skillet to 170–175 °C (340–350 °F).
Fry chicken for 3–4 minutes per side until golden and cooked through.
Drain chicken on a wire rack or paper towels and slice into strips before serving.
Heat oil in a saucepan over medium heat and sauté onion for 5–6 minutes until soft and lightly caramelized.
Add garlic and ginger and cook for 30 seconds until fragrant.
Pour in chicken broth and bring to a simmer.
Stir in curry roux until completely dissolved.
Add soy sauce and honey, then simmer for 5–10 minutes until sauce thickens and becomes glossy.
Serve cooked rice topped with sliced chicken katsu and pour warm curry sauce over or alongside.
Garnish with chopped green onions, sesame seeds, and pickled ginger if desired, and serve immediately.