Heat olive oil in a large pot over medium heat. Add chopped onion and minced garlic; sauté until fragrant and translucent (about 5 minutes).

Stir in diced sweet potatoes and carrots; cook for another 5 minutes until slightly softened.

Add rinsed lentils along with cumin, paprika, thyme, salt, and pepper; mix well.

Pour in vegetable broth to cover the mixture. Bring to a boil, then reduce heat to simmer uncovered for about 30 minutes or until lentils are tender.

Taste and adjust seasoning as necessary. Serve hot, optionally garnished with fresh herbs or a dollop of yogurt.