Heat the oil in a large saucepan over medium-high heat, add the onion, celery, and carrots, and sauté until starting to get tender, about 7-10 minutes.
Add the garlic, ginger, rosemary, thyme, turmeric, and cayenne, and cook, mixing, until fragrant, about a minute. Add the flour and stir until the flour is incorporated.
Add the stock, rice, and chicken, bring to a boil, reduce the heat and simmer, covered, until the rice is just tender, about 20 minutes.
Remove the chicken and shred using two forks or chop the chicken into small pieces. Add the chicken back into the soup.
Add the lemon juice, half & half and season with salt and pepper to taste. Stir in chopped parsley and serve.