Preheat your oven to 400°F (200°C). Toss the cubed squash with a tablespoon of olive oil, salt, and pepper, then spread it out on a baking sheet. Roast for about 25-30 minutes until tender and slightly caramelized, filling your kitchen with a sweet, roasted aroma.
While the squash roasts, in a mixing bowl, combine the shredded chicken with the cream of mushroom soup, cinnamon, and a pinch of salt and pepper. Stir until everything is evenly coated and set aside.
Once the squash is ready and slightly cooled, gently fold the roasted cubes into the chicken mixture. This will create a colorful, textured filling ready for baking.
Transfer the mixture into a baking dish, spreading it out evenly. Sprinkle the shredded cheese over the top for a melty, golden crust.
Bake the casserole in the preheated oven for 20-25 minutes, until bubbling around the edges and the cheese is melted and golden brown.
Remove the casserole from the oven and let it rest for a few minutes. The sauce will thicken slightly, and the top will develop a beautiful, toasted appearance.
Serve hot, garnished with a sprinkle of fresh herbs if desired. Enjoy the cozy flavors and satisfying textures of this seasonal casserole.
