01 - Heat olive oil in a large pot over medium heat. Add the onion, carrots, and celery. Sauté for 5-7 minutes until the vegetables are softened and the onion becomes translucent.
02 - Stir in the garlic, ground cumin, smoked paprika, and ground coriander. Cook for 1 minute, stirring constantly, until fragrant.
03 - Add the rinsed lentils, drained diced tomatoes, vegetable broth, bay leaf, black pepper, and salt. Stir to combine and bring to a rolling boil.
04 - Reduce heat to low and simmer uncovered for 35-40 minutes, or until the lentils are fully tender and the flavors have melded together.
05 - Remove and discard the bay leaf. Stir in the fresh lemon juice and adjust salt and pepper to taste.
06 - For a creamier consistency, partially blend the soup using an immersion blender, leaving some texture intact.
07 - Ladle into bowls and serve hot, garnished with freshly chopped parsley. Drizzle with olive oil if desired.