Start by butterflying the boneless skinless chicken breasts and gently pounding them to a uniform thickness of about ½ inch. Season both sides generously with salt and black pepper.

Set up your breading station by arranging three shallow dishes: one filled with all-purpose flour, another with a beaten egg, and the last with panko breadcrumbs. Dredge each piece of chicken in flour, dip it into the egg, then press into the panko until they adhere well.

In a deep pan, heat vegetable oil to 340°F (170°C). Once hot, carefully place the breaded chicken into the pan and fry for 3-4 minutes on each side until golden-brown. Transfer to a wire rack to drain excess oil.

While the chicken fries, heat olive oil over medium heat in a separate pot. Sauté chopped yellow onion and minced garlic for about 3-4 minutes until fragrant.

Add diced carrots and potatoes to the pot, sautéing for an additional 2-3 minutes. Pour in chicken stock and water, followed by soy sauce, honey, and grated red apple. Stir well and bring to a gentle simmer.

Add Japanese curry roux to the pot, stirring until it dissolves completely. Allow the curry to simmer for about 15 minutes, stirring occasionally.

To serve, slice the crispy chicken katsu into strips and place over cooked white rice. Generously ladle curry sauce over the chicken and rice.