Lentil Sausage Soup

This is a delightful soup brought to you by The Barefoot Contessa (Episode: Tale of Two Soups). It's the perfect soup for a cold winter night with a wonderful meaty flavor in which thick rich lentils add to the hardiness of this flavorful soup. We often have bulk mild Italian sausage on hand which is easily subbed for the kielbasa, just brown in a separate pan and add at the same time.

Ingredients
1 pound French green lentils (recommended: du Puy)
1/4 cup olive oil, plus extra for serving
4 cups diced yellow onions (3 large)
4 cups chopped leeks, white and light green parts only (2 leeks)
1 tablespoon minced garlic (2 large cloves)
1 tablespoon kosher salt
1 1/2 teaspoons freshly ground black pepper
1 tablespoon minced fresh thyme leaves
1 teaspoon ground cumin
3 cups medium diced celery (8 stalks)
3 cups medium diced carrots (4 to 6 carrots)
3 quarts Homemade Chicken Stock, or canned broth
1/4 cup tomato paste
1 pound kielbasa, cut in 1/2 lengthwise and sliced 1/3-inch thick
2 tablespoons dry red wine or red wine vinegar
Freshly grated Parmesan, for serving

Directions
In a large bowl, cover the lentils with boiling water and allow to sit for 15 minutes. Drain.

In a large stockpot over medium heat, heat the olive oil and saute the onions, leeks, garlic, salt, pepper, thyme, and cumin for 20 minutes, or until the vegetables are translucent and tender. Add the celery and carrots and saute for another 10 minutes. Add the chicken stock, tomato paste, and drained lentils, cover, and bring to a boil. Reduce the heat and simmer uncovered for 1 hour, or until the lentils are cooked through and tender. Check the seasonings. Add the kielbasa and red wine and simmer until the kielbasa is hot. Serve drizzled with olive oil and sprinkled with grated Parmesan.