Heat the olive oil in a large pot over medium heat. Add the onion and cook until it softens, about 5 minutes. Stir in the garlic and carrots and cook for another 2 minutes.
Add the lentils, cumin, coriander, cinnamon, turmeric, and paprika. Stir to coat the lentils and vegetables with the spices. Pour in the vegetable broth and diced tomatoes. Bring the mixture to a simmer.
Cover the pot and cook for 25 minutes, stirring occasionally, until the lentils and carrots are tender. Stir in the chickpeas and cook for 5 more minutes. Season with salt and pepper to taste.
Ladle the stew into bowls and top each serving with chopped cilantro. Serve with lemon wedges on the side.