Step 1
Place a rack in upper third of oven; preheat to 425°. Start by assembling all the ingredients for the salsa: Remove husks from 12 oz. tomatillos and rinse. Cut any larger ones in half and arrange on a baking sheet.
Step 2
Smash 8 garlic cloves with the flat side of your knife and remove skins. Add to baking sheet with tomatillos.
Step 3
Trim ends of 4 scallions and discard, then cut scallions crosswise into 1" pieces. Add to baking sheet.
Step 4
Cut 1 jalapeño in half lengthwise, pull out stem and ribs, and place on baking sheet. Wash hands!
Step 5
Drizzle 2 Tbsp. oil over vegetables; season with salt. Toss with hands to coat, then push vegetables to one side of baking sheet so they’re taking up about one-third of sheet; set aside.
Step 6
Pat 8 chicken thighs dry with paper towels. Season all over with salt.
Step 7
Whisk 2 Tbsp. adobo sauce (from 1 can chipotles in adobo), 1 tsp. honey, ½ tsp. cumin, and 2 Tbsp. oil in a large bowl until smooth.
Step 8
Add chicken to bowl and toss with tongs until coated. Using tongs, arrange chicken, skin sides up, in center of baking sheet, placing close together so there’s still space left for the squash.
Step 10
Cut 1 acorn squash in half and scoop out seeds with spoon. Cut each half in thirds again to make 6 equal wedges. Arrange squash on baking sheet next to chicken, then drizzle squash with 2 Tbsp. oil. Season with salt and sprinkle with remaining ½ tsp. cumin.
Step 11
Roast until chicken thighs are browned on top and meat is cooked through, tomatillos are lightly charred on top, and squash is fork-tender 30–40 minutes.
Step 12
Transfer chicken and squash to a platter.
Step 13
Tip all remaining ingredients, along with about ½ cup of pan juices, into a blender. Add cilantro, stems and all; season with a bit more salt. Blend, thinning with more pan juices if needed, until smooth and pourable.
Step 14
Let cool slightly. While chicken is cooling, pick about ½ cup cilantro leaves from bunch, reserving stems, and set aside for serving.
Step 15
Pour salsa over platter and top with reserved cilantro leaves. Serve with lime wedges alongside.
