Heat olive oil in lidded skillet. Stir in orzo pasta and cook until golden brown. Stir in onion and cook until onion becomes translucent. Then, add garlic and cook for 1 minute. Dice celery stalks and add. Cook mixture for 1 minute. Mix in the rice, salt and chicken broth. Increase heat to high and bring to a boil. Reduce heat to medium-low, cover, and simmer until the rice is tender, 25 to 30 minutes or until all water is gone. Remove from heat and let stand for 5 minutes, then fluff with a fork.