In a large pot heat butter (or olive oil) over medium-high heat until hot and shimmering. Add onion, carrots, and celery. Cook 3-4 minutes stirring occasionally until tender and translucent.
Add chicken broth and water, bring to a boil.
At a roiling boil add the rice and parsley. Cover, reduce to medium heat and cook for 15 minutes or until the rice is tender. Serve immediately.
