Stir in the bay leaf and the spices (cumin, chili powder, coriander, paprika, cayenne). You can add half the spices and add more later if you prefer.
Stir in the can of tomatoes (including juice), broth, and lentils. Bring to a boil, reduce heat, and then simmer, uncovered, for about 20-25 minutes, until lentils are tender and fluffy.
Stir in kale or spinach and season to taste adding more spices if you wish.