1 bunch mustard greens, tough stems removed, leaves torn
Lightly season chicken thighs all over with salt and pepper. Heat vegetable oil in a large Dutch oven or other heavy pot over medium-high. Working in 2 batches and pouring off all but 2 Tbsp. fat between batches, cook chicken, skin side down, until skin is browned and crisp, 10-12 minutes. Transfer to a plate, placing skin side up
Cook white and pale green parts of scallions, chiles, and ginger in same pot, stirring often, until scallions and ginger are golden, about 3 minutes. Add wine, bring to a simmer, and cook until reduced to about 3 Tbsp., 5 minutes. Add soy sauce, brown sugar, sesame oil, and 1 cup broth and bring to a simmer, stirring to dissolve sugar. Return chicken to pot, placing skin side up and overlapping if needed. Partially cover pot, reduce heat, and simmer until chicken is cooked through, 25–30 minutes. Transfer chicken to a plate and place in a warm oven to keep warm
Add squash and remaining 1 cup broth to pot and push in squash so it’s mostly submerged. Arrange greens on top. Bring to a simmer, partially cover pot, and cook until squash is barely fork-tender and greens are wilted, 10–12 minutes. Uncover, increase heat to medium, and continue to cook until liquid is reduced by about two-thirds and has the consistency of thin gravy, 10–15 minutes.
can be served over rice if desired