Chicken Donburi with Spinach

Ingredients

• 1 tablespoon canola or other neutral cooking oil
• 9 medium cloves garlic, 8 halved and 1 minced, divided
• One 10-ounce bunch spinach, thoroughly washed and spun dry
• Kosher salt
• 1/2 teaspoon sesame oil
• 1/2 teaspoon rice vinegar
• 2 boneless, skin-on chicken breast halves, tender removed; or 2 boneless, skin-on thighs and 2 boneless, skin-on drumsticks
• 1/4 teaspoon mayonnaise, optional
• 1/4 cup sake
• 1/4 cup dashi, either instant or homemade
• 1/4 cup soy sauce
• 2 tablespoons mirin
• 1/2 teaspoon cornstarch, stirred into 1 tablespoon water to make a slurry
• 1 tablespoon unsalted butter
• To Serve:
• 6 cups cooked, short-grain Japanese rice
• Kizami nori
• 4 egg yolks, optional
• 2 scallions, sliced thinly
• Kizami beni shoga

Directions

1. Warm the oil in a 10-inch cast iron skillet set over medium heat, stopping when the surface begins to glimmer. Scatter in the sliced garlic and cook, stirring often, until the pieces are evenly golden, about 7 minutes; watch closely so they do not scorch. Lift the garlic out and set it aside. Add the spinach to the same skillet, sprinkle with salt, and toss as it cooks until it has collapsed and most of the moisture has cooked off, about 5 minutes. Take the pan off the heat, stir in the remaining 1 clove minced garlic, and let the residual heat bring out its aroma, about 30 seconds. Add the sesame oil and vinegar, toss everything together, then move the spinach to a plate. Wipe the skillet clean with a fresh kitchen towel; no washing needed.
2. If using chicken breasts, place the skillet back over medium-high heat and let it get hot enough that it is barely beginning to smoke. While it heats, spread a thin coat of mayonnaise over the chicken skin, if using; otherwise just continue on. Salt the breasts, then set them in the pan with the skin facing down. For the best browning, you can set a cooking weight over each breast. Cook until the skin is deeply browned and crisp, about 5 minutes. Turn the breasts over, reduce the heat to medium-low, and cook until a thermometer placed in the thickest section reads 150 degrees F (65 degrees C), about 6 minutes. Move the chicken to a plate so it can rest.
3. If using chicken thighs and drumsticks, put the skillet back on medium-high heat and warm it until it is just beginning to smoke. While the pan heats, coat the chicken skin lightly with mayonnaise, if using; if not, simply keep going. Season the chicken with salt, then lay each piece in the skillet skin-side down. A cooking weight on top of each piece is optional, but helpful for browning. Cook until the skin is crisp and nicely browned, about 6 minutes. Turn the chicken over and keep cooking until a thermometer inserted into the thickest area reads 160 degrees F (71 degrees C); the drumsticks will take about 1 minute more, while the thighs will need about 3 minutes more. Transfer each piece to a plate as it finishes.
4. While the chicken rests, pour the sake into the skillet and cook, scraping the browned bits from the pan, until the sharp alcohol aroma has cooked away, about 1 minute. Stir in the dashi, soy sauce, mirin, and reserved sliced garlic. Bring the sauce to a boil, then lower the heat to medium-low and simmer until it has reduced a little and the garlic is fully tender, about 4 minutes. Add the cornstarch slurry a little at a time, letting the sauce tighten slightly before adding more. Once the sauce is lightly thickened, and you may not need every bit of slurry, turn off the heat. Add the butter, swirling and stirring until it melts completely into the sauce.
5. For assembly, scoop a shy 1 1/2 cups of rice into each bowl. Add kizami nori, if using. Cut the chicken into 1/4-inch-wide slices if using breasts, or deboned 1/4-inch-wide strips if using thighs and drumsticks, then divide it evenly among the bowls. Spoon the sauce over the rice and chicken. Add the cooked spinach and garlic cloves evenly to each bowl. Finish each serving with a raw egg yolk, if using, then add the sliced scallions and pickled ginger, if using. Serve right away, with any extra sauce on the side.