In a large pot, heat the olive oil over medium heat.
Add the onion, carrots, celery, and garlic. Cook until the vegetables are softened, about 5 minutes.
Add the chicken breasts and cook until browned on both sides, about 2 minutes per side.
Add the chicken broth, lentils, rice, thyme, oregano, salt, and pepper. Bring to a boil, then reduce heat to low and cover the pot.
Simmer for 1 hour, or until the lentils and rice are tender and the chicken is cooked through.
Remove the chicken breasts from the pot and shred or chop into small pieces. Return the chicken to the pot.
Taste and adjust the seasoning if needed.
Serve hot and enjoy!