Add the Parmesan cheese and stir until melted and smooth. Season with salt and pepper to taste.
Add the cooked spaghetti, shredded chicken, and frozen peas to the skillet. Stir until everything is well coated with the sauce.
Transfer the mixture to a large baking dish. Bake in the preheated oven for 20-25 minutes, or until the top is golden brown and the sauce is bubbly.
Remove from the oven and let it cool for a few minutes before serving. Enjoy!
Note: You can use leftover cooked chicken or rotisserie chicken for this recipe.
