Cook the noodles and rinse with warm water. Preheat oven to 350 degrees F. Shell Filling: Mix together the chicken, cheddar cheese, sour cream, and 1/2 cup of the marble cheese.
Stuff the individual noodles with the shell filling. Arrange the noodles in a 9x13 casserole dish with the opening face down. Dressing: Mix together the soup, milk, and salsa. Pour the dressing over the noodles.
Cover with foil and bake for 30 minutes. Then remove the foil and cover with the remaining marble cheese. Bake until cheese is melted (5 min). Serve immediately.