Rinse the lentils under cold water and set aside.
In a large pot, heat the olive oil over medium heat.
Add the diced onion and cook for about 4-5 minutes, until softened and translucent.
Stir in the garlic, diced carrots, smoked paprika, and cumin. Cook for an additional 2-3 minutes, stirring occasionally.
Add the rinsed lentils, vegetable broth, and diced tomatoes (with their juice) to the pot. Bring to a boil.
Reduce the heat to low and let the soup simmer uncovered for about 25-30 minutes, or until the lentils are tender. Stir occasionally, adding more broth or water if the soup gets too thick.
Season with salt and pepper to taste.
If desired, garnish with fresh parsley before serving.
Use a ladle to serve the soup into bowls and enjoy warm.