Melt oil in a large, heavy pot over medium heat.Add onion and garlic. Saute 5 minutes or until the onion is soft.Add broth and next 5 ingredients.Bring to a boil. Reduce heat to low.Simmer, uncovered, stirring occasionally, approximately 30 minutes or until lentils are tender. (Red lentils will cook quicker than brown or green.) If using a pressure cooker, bring to a boil.Place the lid on the cooker and bring up to high pressure. Cook for 9 minutes on high [you may need a few more minutes since the tomatoes counteract the cooking of the lentils slightly.Conversely, you could add the tomatoes after cooking the beans and then let the resulting dish cook for a bit].Let pressure come down naturally. Remove lid carefully.)Stir in basil and salt to taste.