In a deep soup pot or 6 quart dutch oven, cook onion, carrot and celery in a couple of drizzles of olive oil. Cook over medium-high for 5 minutes or until softened.
To the pot add chicken stock, rice, bay leaves, salt, pepper, Herbs de Provence, garlic, onion powder and lemon pepper. Mix well. Bring to a boil, then cover and cook over medium-low for 20-25 minutes and rice has softened, stirring occasionally.
Whisk cornstarch into cold half and half until dissolved. Whisk into soup. Add chicken. Taste and adjust salt to your taste. Cook for 3-5 minutes just until lightly thickened and chicken is heated through.
Mix in chopped parsley just before serving. Serve immediately.