1/4 cup olive oil
1 cup frozen chopped onions
4 garlic cloves, chopped
1 celery rib, halved lengthwise and thinly sliced crosswise
2 carrots, halved lengthwise and thinly sliced crosswise
5 1/4 cups reduced-sodium chicken broth (42 fl oz)
2 1/2 cups water
20 refrigerated or frozen precooked meatballs (15-20 oz)
2 14-oz cans small white beans, drained and rinsed
1 bag baby spinach (5-6 oz)
1/2 cup finely grated Parmigiano-Reggiano
Salt and pepper to taste
Heat 2 tbsp oil in a 5- to 6-quart pot over high heat until hot but not smoking, then cook onions, garlic, celery and carrots, stirring occasionally, until onions are pale golden, about four minutes. Stir in broth and water and bring to a boil, covered.
Meanwhile, heat remaining 2 tbsp oil in a 12-inch heavy skillet over high heat until hot but not smoking, then saute meatballs (do not thaw if frozen), turning occasionally, until browned all over, about 3 minutes.
Add meatballs to soup along with beans and briskly simmer, covered, stirring occasionally, until vegetables are tender and meatballs are heated through, about 15 min. Stir in spinach, cheese, salt and pepper and simmer, uncovered, until spinach is wilted, about 1 min. Serve with more grated cheese on top.
[ via Gourmet magazine, February 2006 ]