1Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine the cooked noodles, shredded chicken, diced onion, and tomato sauce. Mix well to ensure all ingredients are evenly distributed.
Transfer the mixture into a greased baking dish, spreading it out evenly.
Sprinkle the shredded cheese evenly over the top of the noodle mixture.
Place the baking dish in the preheated oven and bake for 25-30 minutes, or until the cheese is melted and bubbly, and the dish is heated through.
Remove the dish from the oven and let it cool for a few minutes before serving.
Serve warm and enjoy your Chicken and Cheese Noodle Bake!