In a large pot, heat the oil over moderately low heat. Add the garlic and cook, stirring, for 1 minute. Add the water, broth, and salt and bring to a boil. Reduce the heat and simmer, covered, for 10 minutes.
Meanwhile, in a large pot of boiling, salted water, cook the tortellini until just done, about 4 minutes for fresh or 12 minutes for frozen. Drain.
Add the spinach to the soup and cook until just wilted, about 1 minute. Stir in the tortellini. Serve the soup sprinkled with grated Parmesan and pass more of the grated cheese at the table.
Variations: · Substitute one quart of shredded escarole for the spinach.: · Use meat- or cheese-filled ravioli instead of the tortellini.
Wine Recommendation: Tocai friulano, one of Italy's hidden treasures, bears no relation to the Tokays of Hungary or Alsace. It has a full body and penetrating citrus and nut flavors that will be superb here.