Place Boneless, Skinless Chicken Thigh (1.5 pound) on large cutting board, cover with plastic wrap, then pound out till the chicken is at about 1/4 inch thickness.
Optional step: Marinade chicken in Worcestershire Sauce (4 tablespoon) and Soy Sauce (1 tablespoon) for about 3 hours (or overnight)
Place Egg (2), All-Purpose Flour (1 cup), and Panko Breadcrumbs (2 cup) in three separate shallow dishes.
Heat up Canola Oil (to taste) in pan over medium-high heat about 1/4 inch of oil. Make sure that it's hot enough before frying chicken.
Coat chicken in a thin layer of flour, shake off excess, dip into the egg, then coat in panko breadcrumbs.
Fry until golden brown or about 3 minutes on each side.
Mix Ketchup (3 tablespoon), Worcestershire Sauce (1 tablespoon), Dry Mustard (1/2 teaspoon), and Soy Sauce (to taste) to make Katsu Sauce.
Serve with steamed rice and katsu sauce and enjoy!