01 - Heat olive oil in a large pot over medium heat. Add onion, carrots, and celery. Sauté for 5-7 minutes until vegetables are softened and onions become translucent.
02 - Stir in garlic, ground cumin, smoked paprika, and ground coriander. Cook for 1 minute, stirring constantly, until fragrant.
03 - Add rinsed lentils, drained diced tomatoes, vegetable broth, bay leaf, black pepper, and salt. Stir well and bring to a rolling boil over medium-high heat.
04 - Reduce heat to low and simmer uncovered for 35-40 minutes, stirring occasionally, until lentils are fully tender.
05 - Remove and discard the bay leaf. Stir in 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 lentils whole for texture.
07 - Ladle hot soup into bowls and garnish with freshly chopped parsley. Finish with a drizzle of olive oil if desired.