Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine the cooked egg noodles, diced ham, and frozen peas.
In another bowl, mix together the cream of mushroom soup, sour cream, milk, garlic powder, and onion powder.
Season the mixture with salt and pepper to taste.
Pour the soup mixture over the noodle and ham combination and stir until well combined.
Transfer the mixture into a greased 9x13 inch baking dish.
Top the casserole with shredded cheddar cheese.
Cover the dish with aluminum foil and bake for 20 minutes.
Remove the foil and bake for an additional 10 minutes until the cheese is bubbly and golden.
Let it cool for a few minutes before serving.