Hearty Lentil Soup

I will be cooking this lentil soup recipe tonight. I found it in Deborah Madison's "Vegetarian Cooking for Everyone."

Ingredients

2 tbs olive oil
2 cups onions, finely diced
3 large garlic cloves
Salt and freshly milled pepper
3 tbs tomato paste
1/2 cup celery, finely diced
1/2 cup carrot, finely diced
2 bay leaves
1/2 cup parsley, chopped
1-1/2 cups French green or brown lentils, sorted and rinsed
1 tbs Dijon mustard
1 tbs sherry vinegar or red wine vinegar
Celery leaves and parsley, chopped

Directions

1. Heat the oil in a soup pot over high heat.
   
2. Add the onion and saute until it begins to color around the edges, 5 to 7 minutes. Meanwhile, mince or pound the garlic in a mortar with 1 teaspoon salt.
   
3. Work the tomato paste into the onion, then add the garlic, celery and carrot, bay leaves, and parsley and cook for 3 minutes.
   
4. Add the lentils, 2 quarts water, and 1/2 teaspoon salt and bring to a boil.
   
5. Lower the heat and simmer, partially covered, until the lentils are tender, 25 to 35 minutes.
6. Stir in the mustard and vinegar. Taste and add more of either as needed.
   
7. Check the salt, season with plenty of pepper, remove the bay leaves, and serve, garnished with the celery leaves and parsley. The longer the soup sits before serving, the better it will taste.