Creating the Thanksgiving Leftovers Casserole is straightforward if you follow these simple steps:

1. Preheat Oven: Preheat your oven to 350°F (175°C).
2. Prepare Baking Dish: Grease a large casserole dish with butter or cooking spray.
3. Layer Ingredients: Start by spreading the shredded turkey evenly in the bottom of the dish.
4. Add Stuffing: Layer the leftover stuffing over the turkey, spreading it out evenly.
5. Incorporate Vegetables: If using, sprinkle the frozen mixed vegetables over the stuffing.
6. Pour Gravy: Drizzle the leftover gravy all over the layers in the dish.
7. Spread Cranberry Sauce: Add dollops of cranberry sauce on top for a sweet contrast.
8. Make Egg Mixture: In a bowl, whisk together the eggs, milk, garlic powder, onion powder, salt, and pepper until well-combined.
9. Pour Egg Mixture: Pour the egg mixture evenly over the casserole, ensuring all layers are moistened.
10. Top with Cheese: Sprinkle the shredded cheese over the top layer of the casserole.
11. Bake: Place the casserole in the preheated oven and bake for 30-35 minutes, or until the cheese is bubbly and golden.
12. Cool Slightly: Once done, remove the casserole from the oven and let it cool for 5-10 minutes before serving.

By following these steps, you’ll create an incredible casserole that celebrates the essence of Thanksgiving with every bite.