Although some must have a bit of bacon or salt pork in their lentil soup, I oftentimes crave a simple yet full-flavored vegetarian version.  This recipe from Deborah Madison is easy to prepare and will warm you from the inside out.  Although it is probably best to use a mortar and pestle as she directs, I find that I still get very good results by just running the garlic through a press.

Hearty Lentil Soup

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

Heat the oil in a soup pot over high heat.  Add the onion and sauté 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.  Work the tomato paste into the onion, then add the garlic, celery, carrot, bay leaves, and parsley and cook for 3 minutes.  Add the lentils, 2 quarts water, and 1/2 teaspoon salt and bring to a boil.  Lower the heat and simmer, partially covered, until the lentils are tender, 25 to 35 minutes.

Stir in the mustard and vinegar.  Taste and add more of either as needed.  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.

From “Vegetarian Cooking for Everyone” by Deborah Madison