A burst of fresh lemon juice, added just before serving, makes this soup sing.
1-1/2 Tbs. olive oil or canola oil
2 cups finely chopped onion
1 cup finely chopped or diced carrot
1 cup finely chopped or diced celery
1 large or 2 small bay leaves
3 quarts Homemade Chicken Broth or lower-salt chicken broth
3-1/2 to 4 cups shredded, cooked chicken
3 cups cooked-until-barely-tender white rice
10 oz. spinach, well washed and dried, tough stems removed, and chopped into 2-inch piece
1/4 cup chopped fresh dill
1 to 4 Tbs. fresh lemon juice
Freshly ground black pepper
1/2 cup thinly sliced scallions for serving (optional)
Heat the oil over medium-high heat in a large (at least 8-quart), heavy-duty pot or Dutch oven. Add the onion, carrot, celery, and 1/2 Tbs. salt. Cook, stirring occasionally, until the vegetables are softened and lightly browned in places, 4 to 6 minutes. Add the bay leaf or leaves and cook, stirring, about 30 seconds.
Add the broth and bring to a boil. Reduce to a simmer and cook, stirring, until the vegetables are completely tender, 20 to 30 minutes.
Stir in the shredded chicken, the rice, and spinach. Simmer, stirring occasionally, until all are tender and the flavors meld, 5 to 10 minutes.
Stir in the dill and 1 Tbs. of the lemon juice. Taste, and add more lemon juice, 1 Tbs. at a time, if needed, up to 4 Tbs. Season with salt and pepper to taste and garnish each bowl with 1 Tbs. sliced scallion, if you like.