In a large pot, bring water to a boil, add noodles and cook until tender, about 10 minutes.
Drain the noodles.
In a frying pan over medium heat, sauté onion, celery and mushroom with olive oil. Cook until the onion is translucent, about 10 mins.
In a medium mixing bowl combine soup, half of the cheese, sour cream and milk. Mix well.
In a medium bowl crush lays chips, add 1/2 the cheese and mix.
In a 9x12 casserole dish combine tuna and noodles. Add vegetable mixture.
Add sauce to the noodle mixture and combine well.
Top the noodles with the chips and cheese.
Place the dish in the oven preheated to 350 degrees.
Bake for 25-30 minutes or until cheese is melted and casserole is bubbly.