Preparation

1. Sprinkle the chicken with salt and pepper. Allow to rest on the counter for up to 2 hours to come to room temperature.
2. Preheat oven to 375 degrees and line a baking sheet with tin foil.
3. Put 1/2 of the cranberries in a food processor and pulse until you have small pieces. Add them to a medium skillet with the sweet chili sauce and 3/4 cup water. Bring to a boil, reduce the heat and summer until thickened, about 3 minutes. Strain into a medium bowl, pressing to get as much liquid through as possible. Return the liquid to the skillet and simmer until thick and shiny, like a glaze.
4. Meanwhile, in a large bowl, toss brussels sprouts, squash, potatoes, cranberries, rosemary, salt, pepper, and olive oil. Spread evenly in a single layer over baking sheet, arranging the sprouts cut side down as much as possible. Place a wire rack over the vegetables, and lay the chicken on the rack.
5. When the chicken is around the 140 degree mark, about 30 minutes in, remove from the oven and brush on the glaze on the chicken. Return to the oven and continue to cook until an instant-read thermometer reads 165 degrees F, about 15 minutes more. Let the chicken rest 10 minutes before serving.