Heat the oven to 450°F. While the oven is heating, stir the beans, onion, squash, sweet potato and oil in a deep 12-inch oven-safe skillet. Season the vegetables with salt and pepper. Arrange the chicken and thyme sprigs on top and season the chicken with salt and pepper. Pour in 1 3/4 cups broth.
Roast for 1 hour or until the chicken is golden brown and done and the vegetables are tender. Remove the chicken from the skillet, cover and keep warm.
Stir the remaining 1/4 cup broth and the cornstarch in a small bowl. Place the skillet on the stovetop and heat over medium-high heat to a boil. Stir in the cornstarch mixture. Cook for 3 minutes or until the mixture is slightly thickened. Remove and discard the thyme sprigs. Season with salt and pepper. Serve the vegetable mixture with the chicken.
This nutritional information refers to each serving of the entire recipe and not just the products used as ingredients.