Begin by boiling the pasta according to the package instructions to al dente. Once the noodles have cooked, drain them, run them under cold water to stop the cooking process, and set them aside.
In a mixing bowl, combine the cream of mushroom, cream of celery, milk, kosher salt, black pepper, and dried parsley.
Whisk the ingredients together to combine thoroughly.
Add the drained canned tuna and the frozen peas to the creamy mixture, stirring to ensure they are evenly distributed.
Add the boiled pasta into the mixing bowl in batches, stirring so every noodle is incorporated and fully covered.
Pour the creamy tuna noodle mixture into a 9-inch by 13-inch baking dish and spread it out evenly using a silicone spatula or the back of a serving spoon.
Preheat the oven to 375°f.
Add the potato chips to a mixing bowl and lightly crush them into pieces in a separate mixing bowl. Do not make them too fine; you want to be sure they have some texture. Set the chips aside.
Top the Tuna Noodle Casserole Mix with shredded cheddar cheese.
Layer the casserole with crushed potato chips, ensuring even coverage.
Bake the casserole in the preheated oven for 30 minutes. Once the 30 minutes are up, turn the oven to broil on 550°f for 2-3 minutes and let the top brown.
Remove the casserole from the oven and serve hot.