Heat the olive oil over medium-high heat in a large sauce pan with a tight-fitting lid; add onion, bell pepper and carrot and sauté for 2 minutes.
Add garlic and tomato paste and stir for 1 minute. Add lentils and broth; bring mixture to a boil then reduce heat, cover and simmer for 15 minutes.
Add remaining ingredients; cover and simmer for 10 more minutes.