Cook noodles until done. Meanwhile, sautee onions and celery in butter or oil until onions are translucent, about 8 minutes. Add mushroom soup, milk and peas and heat through. When noodles are done, drain and stir in soup mixture, salt, pepper, and cayenne to taste. Pour it all in a casserole dish, sprinkle breadcrumbs and cheese on top. Bake at 350 for 15-20 minutes.
Cayenne pepper is optional -- I tried it after I saw my boyfriend sprinkling some on his dish. Not too much that you need a sip of water, but just enough to give it a little bite. It really adds something to this comfort casserole.