Instructions

1. Cut 2 Persian (or 1/2 English) cucumbers crosswise into 1/4-inch-thick rounds. Place in a medium bowl and sprinkle with 1/2 teaspoon kosher salt and 1/2 teaspoon granulated sugar. Massage the cucumbers with your fingers until slightly softened and the salt and sugar granules are fully dissolved, 1 to 2 minutes.
2. Squeeze the juice from 1/2 medium lemon (about 2 tablespoons) over the cucumbers and toss to combine. Refrigerate until ready to serve, or store in an airtight container for up to 4 days.
3. Melt 3 tablespoons unsalted butter in a small saucepan over low heat. Sprinkle in 3 tablespoons all-purpose flour and stir to combine. Stir gently and constantly, being careful not to scorch the mixture, until the mixture becomes a light blonde color, about 2 minutes. Remove the pan from the heat. Add 1 tablespoon curry powder and stir until combined.
4. Prepare the following, adding each to a medium bowl as you complete it: Peel 1 medium carrot and cut crosswise into 1/2-inch-thick rounds, trim 1 large celery stalk cut on a crosswise into 1-inch pieces, and peel and cut 1 medium potato into 1-inch chunks.
5. Halve 1 medium yellow onion. Cut each piece lengthwise into thirds, then cut crosswise into 1-inch pieces. Peel and mince a 1 1/2-inch piece of ginger (about 1 tablespoon). Mince 1 garlic clove. Pat 1 1/2 pounds chicken thighs dry with paper towels, then cut into 1-inch chunks.
6. Heat 1 tablespoon of the vegetable oil in a large Dutch oven over medium-high heat until shimmering. Add the onion and cook, stirring occasionally, until beginning to soften and lightly brown, about 2 minutes.
7. Push the onion to the edges of the pot. Add the remaining 1 tablespoon vegetable oil to the center of the pot, then add the chicken to the center of the pot. Cook, stirring occasionally, until the chicken goes from pink to white but isn’t fully cooked, 2 to 3 minutes. Sprinkle in the ginger and garlic and cook, stirring, for 1 minute. If the chicken is sticking to the bottom of the pot, add 1 tablespoon vegetable oil more.
8. Add the carrots, celery, and potato. Cook, stirring occasionally, for 1 to 2 minutes. Add 3 cups broth or water and carefully scrape up any browned bits from the bottom of the pot. Bring the liquid to a simmer. Meanwhile, peel 1 small apple and grate on the large holes of a box grater.
9. Add the grated apple and the curry roux to the pot and stir until the roux is dissolved. Add 2 tablespoons soy sauce, 1 teaspoon rice vinegar, 1 teaspoon kosher salt, and season with black pepper. Stir to combine and return to a simmer.
10. Reduce the heat to medium or medium-low to maintain a gentle simmer. Simmer until the vegetables are tender but aren’t falling apart, about 20 minutes. Meanwhile, trim 4 ounces green beans and cut into 1-inch pieces. If using fresh corn on the cob, cut the kernels from 1 ear until you have 1/2 cup corn kernels.
11. At this point, our curry should be slightly thickened but still pourable. If it’s too thick, add more water or broth as needed, and return to a simmer. Add the green beans and corn, stir to combine, and simmer until the green beans are tender, about 10 minutes more. Taste for season with more soy sauce and kosher salt as needed. The curry should be rich and delicious with a balance among the 5 tastes (sweet, salty, sour, bitter, and umami).
12. Serve immediately over rice, noodles or with crusty bread, with the cucumber pickles on the side.
13. Peeled, grated Asian pear can be used in place of the apple.
14. For a vegan or vegetarian alternative, replace the butter with coconut oil and the chicken with tofu.
15. For a gluten-free version, season with tamari instead of soy sauce and make the roux with mochiko rice flour instead of all-purpose! The roux will not form into a paste the same way, but once added to the broth, the rice flour will thicken the broth much like the flour does.
16. The curry roux is excellent to make ahead in batches and keep on hand in the fridge or freezer. Multiply the roux recipe as desired (3 tbsp butter, 3 tbsp flour, 1 tbsp Japanese curry powder), make in one big batch all together, and then pour the roux into the cavities of a muffin tin to firm up. Be sure to divide evenly among the cavities and divide only into as many cavities as you multiplied the recipe for. Refrigerate or freeze until firm, about 1 hour or overnight, and then remove from the mold. Wrap airtight in plastic or wax paper. Refrigerate for up to 1 month or freeze for up to 4 months.
17. The cucumber pickles can be made and refrigerated in an airtight container up to 3 days ahead.
18. The full recipe can be made ahead of time and stored in the fridge to be reheated and served. The curry will thicken with refrigeration. To reheat, transfer to a pot on the stove, loosen with about 1/2 cup room-temperature water, stir to combine, and allow to come to a simmer. Stir occasionally to prevent sticking, but be careful not to break apart the tender vegetables.