Heat olive oil in a large pot over medium heat.
Add the diced onion and cook until translucent, about 5 minutes.
Add the minced garlic, sliced carrots, and celery. Cook for another 5 minutes.
Stir in the cumin and paprika, cooking for 1 minute.
Add the black lentils, diced tomatoes, and vegetable broth. Bring to a boil.
Reduce heat to a simmer, cover, and cook for 30-35 minutes, or until lentils are tender.
Season with salt and pepper to taste.
Stir in the fresh spinach and cook until wilted, about 2 minutes.
Serve hot and enjoy!