What you need:
1 pound white navy beans (you can used canned, just drain and rinse well)
4 tbsp. olive oil
3 leeks (about 1 pound), both green and white parts, chopped fine; or 3 cups chopped onions.
5 celery stalks, chopped
3 garlic cloves, minced
1 1/2 cups minced carrots (about 3 carrots)
1 small fennel bulb, cored, trimmed, and minced
5 cups water, Roasted Vegetable Stock, (make your own or go to Trader Joe's and buy their low sodium vegetable stock)
1 1/2 tsp. chopped fresh rosemary, or 1 teaspoon ground fennel seed (optional)
1 tsp. salt to taste
Fresh-ground black pepper to taste
2 tbsp. lemon juice (from about 1/2 lemon)
1/3 cup grated Parmesan or Asiago cheese (go easy with this part, but a little won't do you any harm and tastes great)
What to do:
1. Soak the beans overnight in at least 3 quarts of water, or use canned white beans and drain and rinse well (that's what I do). If you are soaking them, drain and rinse well.
2. In a heavy stockpot, heat 2 tbsp. of the olive oil over medium heat. Add the leeks or onions, and cook for 5 minutes, stirring frequently. Add the celery, garlic, carrots, and or stock, the rinsed navy beans, the herbs, and the salt and pepper. Bring the soup to a boil, then reduce the heat and let simmer over low heat, covered, for an hour.
3. Ladle 4 cups of the soup into a blender or food processor. Puree this portion, then pour it back into the pot. Correct the seasonings, adding the lemon juice and perhaps more pepper. Ladle the soup into bowls and drizzle with the remaining olive oil . Sprinkle with the cheese and serve at once.