• 0.5 teaspoon kosher salt (such as Diamond Crystal) or 1/4 teaspoon fine salt, plus more as needed
• 1 pound ground chicken
• 1 large egg
• Neutral-tasting oil, for the pot
• 1 medium yellow onion, chopped
• 3 ounces Japanese curry roux or mix (see Tip)
• 1 medium sweet potato or 1 small winter squash (about 8 ounces), peeled and cut into large chunks
• 2 medium bunches mature spinach or Swiss chard (about 16 ounces), tough stems removed and roughly torn
• Steamed white rice, to serve
Steps
Step 1In a large bowl, combine panko with scallions, garlic, ginger, soy sauce, sugar, pepper and salt. Knead the mixture with your hands until the bread crumbs have broken down and absorbed all the moisture. Add the chicken and egg, and continue kneading vigorously until everything is evenly incorporated and the mixture is sticky, 2 to 4 minutes. (Alternatively, mix the meat in a stand mixer with a paddle attachment.) Moisten your hands with cold water and roll the meat mixture into Ping-Pong-sized balls (about 1 1/2 inches across or 2 tablespoons each).
Step 2Heat a large Dutch oven or heavy-bottomed pot over medium. Add enough oil to coat the bottom of the pot, then add the meatballs. Cook, undisturbed, until deeply browned, then flip to brown the other side, about 3 minutes per side. Transfer to a clean plate.
Step 3If the pot is dry, add more oil. Add the onion, a splash of water and a big pinch of salt, and cook, stirring frequently and scraping up any browned bits, until onion is translucent, 2 to 4 minutes. Add the sweet potato and 3 cups of water. Bring to a boil, then reduce the heat to gently simmer until tender, about 10 minutes.
Step 4Chop the curry roux into small pieces, then add to the pot along with the meatballs and any juices that have collected on the plate. Simmer gently, stirring occasionally, until the roux has dissolved and the liquid has thickened, about 5 minutes. (If the curry is too thin, simmer gently until it reaches your desired consistency. If it’s too thick, add water to thin.) Add the spinach or chard and gently fold into the curry to wilt. Serve with rice.
