This is a thin chicken soup—a warming but not super‐filling first course—with the rice, meat, and vegetables acting as a garnish rather than a major player; see the variation if you want something more substantial. Use orzo or other tiny pasta, angel hair or other thin noodles, ribbons or other egg noodles, or other cooked grains in place of the rice.
Place the stock in a large, deep saucepan or casserole and turn the heat to medium‐high. When it is just about boiling, turn the heat down to medium so that it bubbles but not too vigorously. Stir in the rice, carrot, and celery and cook, stirring occasionally, until they are all tender, about 20 minutes.
Stir in the chicken. If it is raw, cook another 5 to 8 minutes, until it is cooked. If it is cooked, cook 2 or 3 minutes, until it is hot. Season with salt and pepper, garnish, and serve.