Heat olive oil in a large pot over medium heat until shimmering (about 2 minutes). Add chopped onion, carrots, and celery; sauté until soft and slightly golden, about 5 minutes.

Add minced garlic, ground cumin, salt, and pepper; cook for 1 minute, stirring constantly, until fragrant.

Pour in diced tomatoes and vegetable broth, scraping up any browned bits from the pot bottom. Increase heat to high, bring to a gentle boil.

Stir in rinsed lentils and bay leaves; reduce heat to low. Cover and simmer for 25–30 minutes, until lentils are tender.

Discard bay leaves, taste the soup, and adjust seasoning with extra salt, pepper, or a squeeze of lemon juice.

Serve hot in bowls, topping each with a sprinkle of parsley or cilantro.