Creating Tuna Noodle Casserole is simple when you follow these clear steps:

1. Preheat the Oven: Begin by preheating your oven to 350°F (175°C).
2. Cook the Noodles: In a large pot, bring water to a boil. Add the egg noodles and cook according to package instructions until al dente, then drain and set aside.
3. Mix Ingredients: In a large mixing bowl, combine the drained tuna, cream of mushroom soup, frozen peas, milk, shredded cheddar cheese, garlic powder, onion powder, salt, and pepper. Stir well to combine.
4. Combine Noodles: Add the cooked egg noodles to the tuna mixture, thoroughly mixing until all ingredients are well combined.
5. Transfer to Casserole Dish: Pour the mixture into a greased 9×13-inch casserole dish, spreading it evenly.
6. Prepare Topping (Optional): If using breadcrumbs, mix them with melted butter in a small bowl. Sprinkle evenly over the casserole for a crunchy topping.
7. Bake: Place the casserole in the preheated oven and bake for 30-35 minutes, or until it bubbles and the top is slightly golden.
8. Cool and Serve: Remove from the oven and let it cool for about 5-10 minutes before serving to allow the flavors to meld.