Bring a large pot of water to a boil and salt generously. Cook the pasta until it is al dente, about 8-10 minutes.
While the noodles are cooking, preheat the oven to 425ºF. Spray a 9x13-inch casserole dish with nonstick cooking spray.
Place a large skillet over medium-high heat and heat the olive oil. Add the onion and the mushrooms and cook until the mushrooms are soft and the onion is translucent. Season with salt and pepper.
In a large bowl, combine the condensed soup, tuna fish, 1 cup of the cheese, the peas, the sour cream, and the cooked mushrooms and onions. Stir to combine.
When the noodles are done, drain, then add to filling mixture. Stir gently to combine.
Pour the mixture into the prepared casserole dish.
Cover the casserole with foil and bake for 15 minutes.
Remove from the oven and top with the remaining 1 cup of cheese and the crushed potato chips. Return to the oven and cook uncovered for an additional 10 minutes, or until the cheese is melted.
