Combine the Ingredients: Place the chicken thighs, butternut squash, and red onion on a large sheet pan. Add the kale pesto, salt, and black pepper. Toss well to coat everything evenly in the pesto.
Roast: Spread the mixture into an even layer. Roast for 40–45 minutes, or until the butternut squash is tender and the chicken reaches an internal temperature of 165°F.
Rest and Serve: Remove from the oven and let rest for 10 minutes before serving. Serve hot.