Gather all ingredients.
Fill a large pot with lightly salted water and bring to a rapid boil. Cook egg noodles at a boil 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 well combined.
Transfer the mixture into a 9x13-inch baking dish.
Top the mixture with crushed potato chip and remaining 1 cup of cheese.
Bake in the preheated oven until cheese is bubbly, about 15 to 20 minutes.
Serve hot and enjoy!