This French Lentil Soup is adapted from my mom's recipe, which she made for us regularly growing up. I've tweaked it slightly, mainly by adding the tarragon and crème fraîche at the end - the addition of just a little bit of soured cream and sweet anise flavor really brings the dish together for me, and makes it taste quintessentially French.
Green lentils take longer to cook than brown, red, or yellow, but they hold their shape better than the latter. That being said, you could get by with brown lentils, just bear in mind they cook a little quicker and will go a bit mushy. This isn't really a problem, though, as the soup is pretty rustic anyway, and you'll have plenty of crusty bread to help sop it all up.
French Lentil Soup
In a large stockpot over medium heat, add oil. Once hot, add onion, garlic, carrot, 1/2 teaspoon salt, 1/4 teaspoon pepper, and thyme; sauté until onions begin to soften, 5 minutes. Deglaze pan with wine and reduce by half, scraping up any bits that have stuck to the bottom. Whisk in tomato paste. Add lentils and broth, stirring everything together. Bring to a boil, reduce heat, cover, and simmer until lentils are tender and cooked through, 50 minutes - 1 hour.
Once lentils are cooked, reduce heat to low. Ladle one cup of lentils into a small bowl; stir in crème fraîche (to help slightly cool the soup before puréeing). Transfer to a food processor and add tarragon. Purée mixture until smooth and return to pot. Stir in remaining 1/2 teaspoon salt and 1/4 teaspoon pepper. Serve immediately with crusty bread and butter.
2 tablespoons olive oil
1 large onion, chopped
3 cloves garlic, minced
3 carrots, peeled and cut into 1-inch pieces
1 teaspoon salt
1/4 teaspoon fresh cracked pepper
3 sprigs thyme, leaves chopped
1/4 cup dry white wine
2 tablespoons tomato paste
6 cups chicken or vegetable stock
1 1/2 cup green lentils (look for French or Puy), rinsed and drained
1/4 cup crème fraîche
1/4 cup fresh tarragon leaves