Slice each boneless chicken breast horizontally to make 2 thinner cutlets or place whole breasts between plastic wrap and pound to about 1/2-inch thickness using a meat mallet. Trim any excess fat. Season both sides evenly with kosher salt, black pepper, and garlic powder.

Set up breading station

Place the flour in a shallow bowl. In a second bowl whisk the eggs with the milk until combined. Put the panko breadcrumbs in a third shallow bowl. If desired, toss the panko with a pinch of salt for flavor.

Bread the chicken

Dredge each seasoned cutlet in flour, shaking off excess. Dip into the egg mixture, allowing excess to drip back into the bowl. Press firmly into the panko breadcrumbs, coating completely and pressing to adhere. Transfer to a tray and rest for 10 minutes so the coating sets.

Heat oil

Pour vegetable oil into a heavy-bottomed skillet or Dutch oven to a depth of about 1"–1.5" (roughly 3–4 cups). Heat over medium-high until the oil reaches 340–350°F (170–175°C). If you don’t have a thermometer, test with a small piece of bread: it should brown in about 45–60 seconds.

Fry the cutlets

Working in batches to avoid overcrowding, carefully lower breaded cutlets into the hot oil. Fry 3–4 minutes per side, until evenly golden brown and the internal temperature reaches 165°F (74°C). Adjust heat as needed to maintain 340–350°F so the coating crisps without burning. Transfer cooked cutlets to a wire rack set over a sheet pan or paper towels to drain. Lightly brush with a little neutral oil if you want an extra sheen.

Rest and slice

Let the cutlets rest 2–3 minutes, then slice into strips across the grain for serving.

Katsu Dipping Sauce

Combine ketchup, soy sauce, Worcestershire sauce, mirin (if using), brown sugar, rice vinegar, grated ginger, and sesame oil in a small bowl. Whisk until smooth. Add hot water 1 tablespoon at a time to reach a slightly pourable but still thick dipping consistency (about 2 tbsp). Taste and adjust sweetness or salt with a little more brown sugar or soy sauce as desired. Transfer to a small serving bowl.

Rice and Mac Salad (side)

Cook rice

Rinse the short-grain rice under cold water until the water runs mostly clear. Combine rinsed rice, 1 1/4 cups water, and 1/4 tsp salt in a small saucepan. Bring to a simmer, reduce heat to low, cover, and cook 15 minutes. Remove from heat and let sit, covered, 10 minutes. Fluff with a fork and keep warm or cool slightly for plating.

Cook macaroni

Bring a pot of salted water to a boil. Cook elbow macaroni according to package directions until al dente (usually 7–8 minutes). Drain and rinse under cold water to stop cooking and cool for the salad.

Make mac salad

In a bowl combine the drained, cooled macaroni with mayonnaise, apple cider vinegar, sugar, 1/4 tsp salt (for the mac), black pepper, and chopped onion or celery if using. Mix until evenly coated. Chill for at least 15 minutes to allow flavors to meld. Taste and adjust seasoning.

Assembly & Serving

Place one scoop (about 3/4 cup) of cooked rice and a scoop (about 3/4 cup) of mac salad on the plate. Arrange sliced chicken katsu next to the sides. Serve with a small bowl of katsu dipping sauce, lemon wedges, and optional sliced green onion sprinkled over the chicken. Enjoy hot.