Add 1 Tbsp olive oil to a large pot over medium-high heat. Add 1 cup chopped yellow onion and 2 diced celery stalks and cook for about 2 minutes, until the onion becomes translucent.
Stir in 4 minced garlic cloves and cook for 30 more seconds, until fragrant.
Stir in 2 chicken bouillon cubes ( or 1 Tbsp chicken stock powder), ½ tsp dried thyme, ¼ tsp ground black pepper, and 1 bay leaf.
Add 1 ½ lbs boneless skinless chicken thighs, 8 cups chicken broth, 2 chopped carrots, and 1 cup uncooked rice to the pot. Stir everything together, then bring to a boil. Once boiling, reduce the heat to a simmer and cook for 20–30 minutes, or until the chicken is cooked through and the rice is tender.
Remove the pot from the heat. Remove the chicken thighs and place them on a plate. Shred the chicken with a fork into small pieces, then return the shredded chicken to the soup. Stir everything together. Taste and adjust the seasoning if needed, then serve!