Heat oil in large saucepan.  Add onions and carrots and cook over medium-low heat for 8 to 10 minutes, until the onions start to brown; stirring occasionally.  Add garlic and cook for 1 minute.



Meanwhile, place canned tomatoes with juice in a food processor and pulse several times until the tomatoes are coarsely chopped.  Rinse and pick over lentils to make sure there are no stones.



Add the tomatoes, lentils, chicken broth, curry powder, thyme, salt and pepper to pan.  Raise the heat to bring to a boil, then lower heat and simmer covered for about 40 minutes, until lentils are tender.  Check occasionally to be sure the liquid is still simmering.  Remove from heat and allow lentils to sit covered for another 10 minutes. Add vinegar and season to taste with salt and pepper.  Serve hot.