Gather all your equipment and ingredients. Chop the carrots into small dice, slice the celery thin, dice the onion, and mince the garlic. Place the chicken breasts in the slow cooker.
Pour in the chicken broth, ensuring it covers the chicken and vegetables. Add the diced carrots, sliced celery, diced onion, minced garlic, bay leaves, and dried thyme. Season generously with salt and pepper, then give everything a gentle stir.
Set the slow cooker to low and cook for 6 to 8 hours, or on high for about 4 hours. The house will fill with a savory aroma as the ingredients gently simmer and meld together.
Once cooking time is up, remove the chicken breasts and shred them with two forks until tender and easy to pull apart. Return the shredded chicken to the broth.
If desired, add noodles or rice to the slow cooker now. Stir, then cook on high for another 15-20 minutes until they are tender and have absorbed the flavors.
Taste the soup and adjust the salt and pepper as needed. Remove the bay leaves and thyme sprigs. The broth should be rich, fragrant, and slightly thickened.
Ladle the steaming soup into bowls. Garnish with fresh herbs if you like, and serve hot for a cozy, comforting meal.
