Place oil and butter in a large pot over medium high heat. Add onion and garlic, cook for 5 minutes until onion is translucent.

Add carrots and celery, stir for 1 minute.

Add stock powder, dried parsley, thyme (if using), pepper, chicken broth, water. Stir, then add chicken.

Cover with lid, simmer on medium low for 30 minutes. Adjust heat so it's bubbling a nice amount, but not crazy energetically or super slowly. Skim off excess foam build up once or twice (not critical, just makes broth clearer).

Remove lid, add rice. Stir, cover, simmer 15 minutes.

Remove soup from stove.

Remove chicken into large bowl. Shred with 2 forks, discard bones then stir into soup.

Stir in half the parsley, taste for salt and add if required. Serve, then garnish with extra parsley.