Heat olive oil in a medium soup pot over medium heat. Sauté onion and carrot until softened and translucent.
Add garlic, cumin seeds, cinnamon, and coriander. Cook until fragrant, about 1 minute.
Stir in tomato paste and mix well. Add lentils and lemon juice, stirring to combine.
Pour in water and stir in Better Than Bouillon until dissolved. Add spinach, reduce heat to medium-low, and cover. Simmer for about 20 minutes, stirring occasionally. Skim off any scum that rises to the top.
Taste, adjust seasoning if needed, and serve hot.