Heat 1 tbsp olive oil in a large soup pot over medium heat. Sauté the yellow onions, carrots, and celery for about 10 minutes, until the onions have browned a bit. Add the garlic, tarragon, thyme, and paprika and cook for another 2 minutes. Add the tomatoes and stir to de-glaze the pot.
Add the broth, lentils, bay leaves, salt and pepper. Cover and bring to a boil. Once soup is boiling, lower heat to a simmer and cook, covered, for about 45 minutes or until the lentils are tender.
Add more water if it looks too thick or cook uncovered until desired thickness is reached if it is too thin. Serve with good, crusty bread.