While noodles are cooking, brown the ground beef and onion in a large skillet over medium high heat. Reduce heat to low, add the tomato sauce, stir well, and let simmer for 1 minute. Add the cream cheese and cottage cheese, stirring together until well blended. Then stir in the egg noodles and sour cream until all ingredients are well mixed. Pour into a 2 quart casserole dish.
Bake at 350 degrees F (175 degrees C) for 30 minutes. Season with salt and pepper to taste.
