Chicken & Stuffing Casserole

Preheat oven to 350°F. Arrange bread cubes in a single layer on a large rimmed baking sheet. Bake until evenly toasted and crisped, about 15 minutes. Let cool for about 10 minutes.

Meanwhile, whisk broth and cornstarch in a small saucepan until smooth. Bring to a boil over medium-high heat, stirring often. Cook, stirring constantly, until thickened and glossy, about 1 minute. Pour into a large heatproof bowl; let cool for about 10 minutes.

Heat 1 tablespoon butter in a medium skillet over medium-high heat. Add onion, carrot and celery; cook, stirring often, until softened, 5 to 8 minutes. Add to the broth mixture in the bowl along with chicken, sour cream, thyme, poultry seasoning, salt and pepper; stir until thoroughly combined.

Measure 1 1/2 cups of the toasted bread cubes into a small bowl, and set aside. Stir the remaining bread cubes into the chicken mixture. Coat a 2-quart baking dish with cooking spray; spoon the chicken mixture into the baking dish.

Place the remaining 3 tablespoons butter in a small microwaveable bowl; microwave on High until melted, about 30 seconds. Add to the reserved bread cubes and toss to coat. Sprinkle evenly over the chicken mixture.

Bake until golden and bubbly, about 30 minutes. Let cool for about 10 minutes. Serve.