- 1 (12 inch) length of crusty baguette, halved lengthwise, then cut crosswise into thirds
- Extra-virgin olive oil for brushing bread
- 2 cups water
- 3 cups reduced-sodium chicken broth
- 1/2 teaspoon salt
- 1/4 teaspoon black pepper plus additional for serving
- 1 (10 ounce) box frozen chopped spinach (not thawed)
- 1/2 cup finely grated Parmigiano-Reggiano plus additional for serving
- 2 large eggs, beaten
- Put oven rack in lower third of oven and preheat oven to 400 degrees F.
- Brush cut sides of baguette with oil. Arrange, cut sides up, on a baking sheet and bake until golden, about 10 minutes.
- Meanwhile, heat water with broth, salt, and pepper in a 2- to 2 1/2-quart saucepan over moderate heat until hot. Stir in frozen spinach and cheese and simmer, covered, stirring occasionally, until spinach is just tender, about 8 minutes.
- Add beaten eggs in a slow, steady stream, stirring constantly.
- Serve with freshly ground pepper and a slice of toasted baguette in the soup.