Gather all ingredients.
Fill a large pot with lightly salted water and bring to a boil. Add egg noodles and cook until tender yet firm to the bite, 7 to 9 minutes; drain. Meanwhile, preheat the oven to 425 degrees F (220 degrees C).
Mix noodles, condensed soup, 1 cup cheese, tuna, peas, mushrooms, and onion in a large bowl until evenly coated.
Transfer the mixture into a 9x13-inch baking dish.
Top the mixture with crushed potato chips and remaining 1 cup of cheese.
Bake in the preheated oven until cheese is melted and edges are lightly golden, about 15 to 20 minutes.
Serve hot. Enjoy!
