Cut the onions into wedges. If you prefer, mince or thinly slice them so they melt into the sauce.
2 onions
Peel the carrots and cut them into rolling wedges (this is called rangiri in Japanese). This cut creates more surface area, helping the carrots absorb more flavor and cook faster.
2 carrots
Peel the potatoes. Cut each potato into quarters. Soak in water for 15 minutes to remove excess starch.
3 potatoes
Grate the ginger. You will need 1 teaspoon of grated ginger, including the juice. Mince the garlic and set aside.
1 teaspoon grated ginger
Cut the apple into quarters, remove the core, and peel.
0.5 apple
Grate the apple.
0.5 apple
Cut the chicken into bite-size pieces. For faster cooking, cut on a diagonal (sogigiri in Japanese) to create more surface area and flatten each piece. Season with salt and pepper.
700 g boneless chicken thighs
Cook the curry
Heat the oil in a large pot over medium heat, then add the onion.
Sauté the onions, stirring occasionally, until translucent and tender, about 5 minutes. Do not stir too often or they won't develop a golden color. Cooked onions add incredible flavor, so do not skip this step.
Add the minced garlic (a garlic press gives a finer texture) and the grated ginger; stir well.
Add the chicken and cook, stirring frequently, until no longer pink on the outside. If the onions brown too much, temporarily reduce the heat to medium-low.
Add the chicken broth. Alternatively, use water, or half broth and half water.
Add the grated apple, honey, soy sauce, sugar, tomato, and vinegar.
Add the carrots and potatoes. The broth should just barely cover the ingredients. Don't worry; we don't want too much liquid at this stage, and extra liquid will be released from the meat and vegetables.
Simmer, covered, over medium-low heat for 15 minutes, stirring occasionally. Simmer uncovered if the ingredients are completely submerged in the broth.
Once it comes to a boil, use a fine-mesh strainer to skim the scum and foam from the surface of the broth.
Continue cooking, covered, until a wooden skewer slides easily through the carrots and potatoes.
Add the curry roux
Turn off the heat. Put 1–2 cubes of roux into a ladleful of the cooking liquid, let it dissolve slowly with a spoon or chopsticks, and stir it back into the pot to incorporate. Repeat with the remaining blocks, 2 cubes at a time.
Simmer, uncovered, over medium-low heat, stirring frequently, until the curry thickens, about 5 to 10 minutes. If the curry is too thick, add water to thin the sauce. When stirring, make sure nothing is stuck to the bottom of the pot; otherwise, it may burn.
If you used homemade curry roux (which contains no salt), taste the curry and add salt to your liking. Tip: The amount of salt varies depending on the brand of chicken broth and the condiments you added, so taste and adjust the seasoning yourself.
Serve
Serve the curry with steamed sushi rice. If you like, garnish with fukujinzuke.
Store
Store leftovers in an airtight glass container (so no staining!) and refrigerate for up to 3 days or freeze for up to 1 month. The texture of the potatoes will change in the freezer, so remove them before freezing. When reheating, add 60–120 ml of water to thin the sauce.
Notes
Meat substitutes: Since tofu, mushrooms, and vegetables cook quickly, you may not need to simmer them for 15 minutes, except for denser vegetables like the carrots and potatoes here. You can sauté mushrooms and vegetables (squash, zucchini, eggplant, etc.) and simmer for 5 minutes or until tender.If you use tofu, you only need to warm it through because tofu is already cooked. I recommend draining it for 15 minutes before using and adding it right after the curry roux goes in. Warm it through for the last 5 to 10 minutes.