Heat a pot and add oil. After oil gets, add chicken breast pieces and sear for 5-7 minutes on both sides until chicken turns slightly brownish.
Remove the chicken pieces and keep them aside.
In the same pot, add onion and sauté till onion turns pinkish.
Add garlic and sauté till garlic turns aromatic.
Mix the vegetables, that is carrot and celery and cook for 4-5 minutes till vegetables turn soft and tender.
Add the chicken pieces back to the pot with vegetables, pour in the chicken broth, bay leaf, pepper and salt and boil nicely on high flame.
Lower the heat to medium and cook the soup for 30-40 minutes or until the chicken is fully cooked.
Again, remove the chicken pieces from the soup and keep them on a plate.
Using 2 forks, shred the chicken and add it back to the soup pot and simmer for 2 minutes.
Taste the soup and adjust salt and pepper if needed.
Garnish with finely chopped celery leaves or parsley.
Serve with lemon wedges for fresh taste.