1In a nonreactive large saucepan over medium heat, heat the oil. Add the onions, tomatoes and garlic; saute 6 minutes until the onions are soft. Add the cumin and paprika, then cook another minute, stirring constantly.
Add the lentils and chicken broth, bring to a simmer. Cook 10 minutes.
Transfer the soup to a blender, in batches if necessary, and puree until smooth. Return the soup to the saucepan. Stir in the lemon zest and juice. Season with salt and pepper; return to a simmer. Ladle into serving bowls and drizzle olive oil over each serving.