Bring a large pot of salted water to a boil. Cook Pasta in boiling water until al dente';drain.
Peheat oven to 425 degrees.
In a large bowl, thoroughly mix noodles,onion,1 cup cheese,peas,tuna and soup. Transfer to a 13 X 9 inch greased baking dish, and top with potato chips and remaining 1 cup cheese. Bake15-20 min.in a preheated oven or until cheese is bubbly. Get your plate ready,and dig IN!