Preheat the oven to 400°F (200°C) and grease a 9x13-inch (23x33 cm) baking dish with cooking spray.
In a large bowl, whisk together the corn muffin mix, milk, chicken broth, and eggs until the mixture is smooth and well combined.
2 boxes corn muffin mix, ⅔ cup milk, ¼ cup low sodium chicken broth, 2 large eggs
Pour the cornbread batter into the prepared baking dish, spreading it evenly across the bottom.
Sprinkle the mixed vegetables evenly over the cornbread batter.
12 ounces frozen mixed vegetables
Layer the shredded chicken on top of the vegetables, spreading it out evenly.
1 pound cooked chicken
Top the casserole with the shredded cheddar cheese, making sure to cover the chicken and vegetables.
8 ounces shredded cheddar cheese
Bake, uncovered, for 35-45 minutes, or until the cornbread is golden brown and the cheese is melted and bubbly.
Let the casserole cool for a few minutes before serving. Enjoy!