Place chicken breasts in a large slow cooker and cover with cold water, 3/4 of the way full. Add vegetable flakes, bay leaf, parsley, tarragon, celery salt and onion. Cook on high at least 6 hours or on low for 8 hours. 1 hour prior to serving add carrots, chicken bouillon, chicken broth and start making drop-in noodles.
In a large stock pot bring 4 to 6 quarts of salted water to a boil. In a mixing bowl combine flour and cheese. In the center of flour mixture make a well and drop in eggs and milk. Mix with a fork until dough crumbles and looks like peas (if too dry add milk; if too moist add flour). Drop pea size dough pieces into boiling water and cook for 20 minutes. Drain and rinse the noodles with cold water.
Once noodles are finished and vegetables in soup are tender, ladle soup into serving bowls, drop in noodles and serve.