In a large pot, place chicken breasts and cover with 1920 ml of water. Add 1 tsp of salt. Bring to a boil, then reduce heat and simmer for 20-25 minutes, or until chicken is cooked through. Skim off any foam that rises to the surface during simmering.

Remove chicken from the pot and set aside to cool slightly. Strain the broth through a fine-mesh sieve into a clean bowl or pot, discarding any solids. You should have about 6-1680 ml of broth. Return the strained broth to the pot.

Once the chicken is cool enough to handle, shred or dice it into bite-sized pieces. Add the shredded chicken, diced carrots, celery, and onion to the strained broth in the pot.

Bring the soup to a simmer over medium heat. Cook for about 10-15 minutes, or until the vegetables are tender-crisp.

While the vegetables are simmering, prepare a roux. In a separate small saucepan, melt the butter over medium heat. Whisk in the flour and cook for 1-2 minutes until lightly golden, stirring constantly.

Gradually whisk about 240 ml of the hot broth from the soup pot into the roux to create a smooth paste. Pour this mixture back into the main soup pot, whisking to combine.

Add the egg noodles, minced garlic, remaining 1 tsp of salt, black pepper, chopped dill, and chopped parsley to the soup. Stir well.

Continue to simmer for another 8-10 minutes, or until the noodles are cooked al dente and the soup has thickened to your desired consistency. Taste and adjust seasoning if necessary.

Ladle the hot soup into bowls and serve immediately.