Lentil-Spinach Soup

Recipe by Deborah Madison, from The Greens Cookbook

(serves 4-6)
1 cup green or brown lentils, picked over and rinsed
1 bay leaf
1 celery stalk, diced
7 cups water
salt
3 Tablespoon olive oil
1 large red onion, finely diced
2 cloves garlic, minced
3 Tablespoons parsley, chopped
3 medium tomatoes, peeled, seeded and chopped; juice reserved
1 bunch spinach, stems removed and leaves washed
red wine or sherry vinegar to taste
pepper
asiago or Parmesan cheese, grated

Put the lentils, bay leaf and celery in a soup pot with the water, reserved tomato juice and 1/2 teaspoon salt. Bring to a boil and scoop off any foam that comes to the surface. Reduce to a slow boil. While the lentils are cooking, heat the oil in a skillet and add the onions and 1/2 teaspoon salt. Cook briskly for a few minutes then lower heat and stir in garlic and parsley. Continue cooking until the onion is soft. Add the tomatoes and cook for 5 minutes, then combine with the cooking lentils. Cut the spinach leaves into half inch strips. There should be about 4 cups. When the lentils are soft, stir in the spinach by handfuls. Once it has cooked down, thin the soup, if necessary, by adding more water, and taste for salt. Simmer the soup for 5 minutes. Serve with fresh ground pepper and cheese.