2 large heads mustard greens, tough stems removed and leaves sliced crosswise in quarters
1 tablespoon kosher salt
2 garlic cloves, smashed
1½ tablespoons Szechuan peppercorns
1 green Thai chile, halved lengthwise
3 cups water
1 tablespoon granulated sugar
3 tablespoons rice vinegar
2 cups jasmine rice
8 cups vegetable or chicken broth
1 teaspoon kosher salt
4 scallions, white and light green parts only, thinly sliced
¼ cup roughly chopped fresh cilantro leaves
¼ cup roughly chopped roasted, salted peanuts
1-inch piece daikon, peeled and sliced into thin matchsticks
1 pound chicken thighs
2 teaspoons kosher salt
1 teaspoon freshly ground black pepper
1 tablespoon canola or grapeseed oil
8 cups vegetable or chicken broth
2 tablespoons dark mushroom soy sauce
1 cinnamon stick
1 whole clove
½ star anise pod
1-inch piece fresh ginger
2 teaspoons granulated sugar
Directions
Pickle the mustard greens: In a large bowl, toss the mustard greens with salt. Add the garlic cloves, Szechuan peppercorns and chile halves and toss to combine. In a medium saucepan set over high heat, bring the water and sugar to a boil. Add the vinegar and pour the hot liquid over the mustard greens. Transfer the greens to a 2-quart container, cover and refrigerate for 3 days, shaking the greens once a day to redistribute the pickling liquid.
Make the rice congee: In a large bowl, add the rice and cover with cold water. Rinse the rice, drain through a fine-mesh sieve and return the rice to the bowl. Repeat twice. Transfer the rice to a large pot and add the vegetable broth, chicken carcasses (if using) and salt. Bring to a boil over high heat, reduce the heat to medium-low, cover and gently simmer until the rice breaks down into a porridgelike consistency, 3 to 4 hours. Remove the chicken carcasses, taste and adjust the salt as needed.
While the congee cooks, make the braised chicken: On a cutting board, season the chicken with the salt and pepper. In a large pot set over medium-high heat, add the oil and heat until hot, about 1 minute. Place the chicken skin-side down in the pot and cook until browned, about 7 minutes. Use tongs to transfer the chicken to a large plate. To the pot, add the vegetable broth, soy sauce, cinnamon stick, clove, star anise, ginger and sugar. Bring to a simmer, return the chicken to the pot, reduce the heat to medium-low and simmer gently until the chicken is cooked through, about 1 hour. Use a slotted spoon to transfer the chicken to a large bowl. Return the braising liquid to a simmer and cook until reduced by one-third and the braising liquid is slightly thicker. Once the chicken is cool enough to handle, remove and discard the skin and bones and cut the chicken into bite-sized pieces. Return the chicken pieces to the braising liquid.
Ladle about ½ cup of congee into 4 bowls. Top with some chicken and braising liquid and some of the pickled mustard greens. Sprinkle with scallions, cilantro, peanuts and daikon and serve.