In a large pot, heat the olive oil over medium heat. Add the onion and fennel and saute for 6 to 7 minutes until translucent. Add the carrots, lentils, tomatoes, broth, water, salt, paprika, and oregano.
Bring to a simmer. Simmer for 22 to 25 minutes until the lentils are tender.
Stir in the spinach and grated garlic, and allow it to rest for 5 minutes before serving. Taste and season with additional salt and fresh ground pepper as necessary. Serve immediately. Stores refrigerated for up to 4 days and frozen for 3 to 4 months.