Cook Spaghetti According To Package Directions. Meanwhile, In A Large Skillet, Saute Onions And Mushrooms In Butter Until Tender; Reduce Heat; To Low. Drain Spaghetti. Add The Spaghetti, Ham, Chicken, Sour Cream, Cottage Cheese, Celery Salt, Salt And Pepper To The Skillet. Cook And Stir Until Heated Through. Remove From The Heat. Sprinkle With Cheese.