Dice the onion into ½-inch pieces, chop the carrot and celery into similar-sized pieces, and mince the garlic cloves.
Heat the oil in a large pot or Dutch oven over medium heat until shimmering.
Add the diced onion, carrot, and celery, stirring occasionally, and cook for 7-10 minutes until the vegetables begin to soften and the onion turns translucent.
Add the minced garlic and thyme to the softened vegetables and stir constantly for about 1 minute.
Pour the broth into the pot and add the chicken chunks, bay leaves, and jasmine rice, stirring to combine everything evenly.
Bring the mixture to a boil over medium-high heat, then reduce the heat to medium-low, cover the pot, and simmer for 20 minutes until the chicken is fully cooked through and the rice is tender.
Remove the pot from heat and carefully fish out the bay leaves and chicken pieces using a slotted spoon.
Return the chicken to the pot and stir in the salt, black pepper, freshly squeezed lemon juice, and chopped parsley.
Ladle the hot soup into bowls and serve immediately.
