1. Heat olive oil in a large pot over medium heat, then add the onion and carrots. Cook for 5 to 6 minutes, stirring often, until softened.

2. Add garlic, tomato paste, cumin, smoked paprika, chili flakes, coriander, salt, and black pepper. Stir for 1 minute until fragrant.

3. Add rinsed lentils, diced tomatoes, vegetable broth, and bay leaf. Stir well and bring to a gentle boil.

4. Reduce the heat and simmer uncovered for 22 to 28 minutes, stirring occasionally, until the lentils are tender and the soup thickens.

5. Blend a small portion of the soup with an immersion blender for a creamier texture, leaving plenty of lentils and vegetables whole.

6. Stir in the spinach and cook for 2 minutes, just until wilted.

7. Remove the bay leaf, stir in lemon juice, then taste and adjust seasoning.

8. Serve hot with fresh parsley or cilantro on top and toasted bread on the side.