"This soup is my families favorite. Very thick and creamy. My dad used to make this for me when I was a child and now I make it for my children. It is perfect for a cold fall day! Store leftovers in a covered container. This soup gets better and better as it sits."
Heat a skillet over medium heat. Add bacon and fry until crisp, 3 to 5 minutes. Pour bacon and grease into a large pot. Add potatoes, corn, celery, onion, carrot, and garlic. Pour in chicken broth and bring to a boil. Reduce heat, cover, and simmer until vegetables are tender, about 15 minutes.
Melt butter in a saucepan over medium heat. Add 3 tablespoons flour and whisk until smooth. Pour in milk, bring to a boil, reduce heat, and simmer until soup is thickened, about 2 minutes.
Beat eggs in a bowl. Add 1 cup flour and stir with a fork until rivel dough is completely moistened.
Mash the soup vegetables lightly in the pot. Add milk mixture. Stir to combine.
Drop teaspoon-sized chunks of rivel dough into the soup a few at a time, stirring as you go to prevent them from sticking together. Cook over low heat until rivels are solid, about 15 minutes. Stir in Cheddar cheese, Swiss cheese, parsley, salt, and pepper.