Heat olive oil in a large pot over medium heat. Sauté the chopped onion and garlic until soft and translucent.
Add the diced carrot and tomato paste. Cook for 3-4 minutes until the vegetables begin to soften and the paste darkens slightly.
Stir in the red lentils, cumin, and paprika, toasting them for about 1 minute to release their flavors.
Pour in the vegetable broth and bring the mixture to a boil. Reduce the heat and let it simmer for 25-30 minutes until the lentils and vegetables are tender.
For a creamier texture, blend half of the soup with an immersion blender and stir it back into the pot.
Season with salt, pepper, and lemon juice. Garnish with fresh parsley before serving.
Notes
If the soup is too thick, add a splash of water or additional broth to reach your desired consistency.