Heat olive oil in a large pan over medium heat.
Add onion and garlic, cooking until softened.
Stir in carrot & pepper and cook for 5 minutes.
Add lentils, chopped tomatoes, tomato paste, vegetable broth, and spices.
Bring to a boil, then reduce heat and simmer for 25–30 minutes, until lentils are tender and the sauce has thickened. Adjust seasoning.