Step 1

Coat the bottom of a large pot with the oil and place it over medium heat.

Step 2

Once the oil is hot, add the onion, carrots and celery. Sweat the veggies for about 5 minutes, stirring often, until they begin to soften up.

Step 3

Add the garlic and cook it with the veggies for about 1 minute, until very fragrant.

Step 4

Stir in the broth, lentils, rosemary, thyme, black pepper, and bay leaf. Raise the heat and bring the liquid to a boil.

Step 5

Lower the heat and allow the soup to simmer for about 25 minutes, stirring occasionally, until the lentils are almost fully cooked but just a bit on the firm side. You can add water while the soup simmers if it becomes too dry.

Step 6

Stir in the tomatoes and let the soup continue simmering for 5 to 10 minutes, until the lentils are tender.

Step 7

Remove the pot from heat and remove the bay leaf. Stir in the vinegar and season the soup with salt to taste.

Step 8

Ladle into bowls and serve.