Collect all the vegetables, chicken, Japanese curry roux, and seasonings. Ensure you have ginger, garlic, apple, honey, soy sauce, and ketchup ready, which are key for enhancing the curry’s flavor.

Cut onions into thick wedges to maintain texture during cooking. Peel and cut carrots into rolling wedges (rangiri style) to create more surface area. Peel and quarter potatoes, soaking them in water for 15 minutes to remove excess starch, which helps them hold shape during cooking.

Grate 1 tsp ginger with juice and mince 2 garlic cloves finely. Peel and core the apple, then grate it for sweetness and depth of flavor.

Trim excess fat from chicken thighs and cut them into bite-sized diagonal pieces (sogigiri) to increase surface area for faster cooking. Season with freshly ground black pepper.

Heat 1½ Tbsp neutral oil in a large pot over medium heat. Add onions and sauté gently without stirring too often, cooking for about 5 minutes until translucent and tender. For more flavor, continue cooking an additional 5 minutes to deepen color.

Add minced garlic and grated ginger to the pot, stirring to combine well with the onions.

Add chicken pieces to the pot, stirring frequently. Cook until the chicken turns opaque on the outside. If onions brown too quickly, reduce heat to medium-low.

Pour in 4 cups chicken stock or broth (or substitute with water as desired). Stir in grated apple, honey, soy sauce, and ketchup to infuse the curry with sweet and umami notes.

Add carrots and Yukon gold potatoes. If using russet potatoes, add them later in the last 15–20 minutes of cooking to prevent disintegration. Ensure the broth barely covers the ingredients to avoid excess liquid.

Cover and simmer on medium-low heat for 15 minutes, stirring occasionally. If ingredients are fully submerged, simmer uncovered. Skim off any scum or foam from the surface using a fine-mesh strainer. Continue cooking until carrots and potatoes are tender when pierced with a wooden skewer.

Turn off heat. Dissolve 1-2 cubes of Japanese curry roux in a ladle of cooking liquid, then stir into the pot. Repeat until all roux cubes are incorporated.

Simmer uncovered on medium-low, stirring frequently to prevent sticking or burning, for 5–10 minutes until the curry thickens. Add water to adjust thickness if necessary. Taste and season with salt if using homemade unsalted roux.

Serve the Japanese chicken curry hot with steamed Japanese short-grain rice on the side. Optionally, garnish with fukujinzuke (Japanese red pickled vegetables) for authentic flavor.

Store leftover curry in airtight containers in the refrigerator for up to 3 days or freeze for up to 1 month (remove potatoes before freezing to preserve texture). Defrost in the refrigerator before reheating.

To reheat, stir in ½ cup water or more to loosen thickened curry sauce, then gently warm on low heat, stirring often to prevent burning. If the sauce is too thin, simmer uncovered to reduce.