Melt the butter in a large Dutch oven or heavy-bottomed pot and saute the onions, carrots, celery, and garlic until softened, about 4 minutes.
Stir in the bay leaf, dried thyme, dried oregano, and parsley flakes.
Pour in the chicken broth, soy sauce, and hot sauce. Add the chicken breasts. Bring to a boil, reduce the heat, and simmer for 15 minutes, or until the chicken breasts are cooked through.
Remove the chicken breasts from the soup, shred them, and return them to the pot.
Add the uncooked rice, and simmer for an additional 10 minutes or until the rice is tender. Serve hot, with freshly chopped parsley on top.