Add the lentils, tomato paste, and broth. Bring to a simmer and cook, covered, until most of the liquid has been absorbed and the lentils and sweet potato are tender, about 25-30 minutes. You may need to add the additional broth as the lentils absorb the liquid.
To make the kale, heat the olive oil over medium heat in a skillet.
Top with fried egg, if desired.
Nutrition facts include 1 egg fried in 2 tsp. olive oil.