Butterfly the chicken by slicing the breast horizontally along the long side of the chicken from one side leaving the other intact.

Fold out the chicken, and lightly pound the chicken to tenderize until it is about ½ inch thick then season both sides with salt and pepper.

Prepare three shallow dishes, 1) with flour, 2) with the lightly beaten egg, and 3) with panko bread crumbs.

Thoroughly coat both sides of the chicken with flour, then the beaten eggs, and lastly the panko bread crumbs. Shake off any excess between each step and make sure to press on the panko bread crumbs to thoroughly coat the chicken.

In a medium-sized deep pan, heat up about 1-2 inches of vegetable or any neutral oil over medium-high heat until it reaches 340°F or 170°C. Place one coated chicken katsu into the oil and cook for 3 minutes before flipping and cooking for another 3-4 minutes. Cook the chicken until golden brown. Let the chicken cool slightly on a wire rack before slicing it into strips.

Peel and dice the potato and carrot into diced pieces about 1 inch thick. Soak the potato in water for about 10 min to remove excess starch. Peel and wedge cut the onion. Peel and mince the garlic. Using a fine grater, grate the apple. Set aside.

In a medium pot over medium heat, add in 1 tablespoon of oil and cook the onion and garlic until lightly browned and fragrant.

When the onions are translucent, add ½ tablespoon of oil and carrot. Mix thoroughly. Cook on medium-high for about 2 minutes.

Add the add ½ tablespoon of oil and the potato. Mix thoroughly. Cook on medium-high for about 2 minutes.

Pour in the chicken stock, soy sauce, honey, and grated apple. Bring the pot to a boil then turn down the heat to medium low, cover the pot and simmer until the potatoes and carrots are soft, about 15 minutes.

Add the curry roux back into the pot with the vegetables and stir gently to blend the curry roux. Simmer on medium low heat for 15 more minutes until the sauce has thickened. Stirring occasionally.

Serve the chicken katsu sliced over a bed of rice and a large scoop of Japanese curry.