Heat the oil in a large skillet or Dutch oven and add the onion. Sauté for a few minutes until it softens.
Stir in the sweet potatoes and cook until they start to soften. Add the garlic and cook for another 30 seconds.
Sprinkle in the taco seasoning, chili powder, salt (to taste) and tomato paste. Stir everything well. Cook for 2 more minutes.
Pour in the lentils, salsa, and broth. Bring the mixture to a boil, then reduce the heat to low.
Cover with a lid and simmer until the lentils and sweet potatoes are tender. Add in the black beans and corn.
Stir and let it simmer uncovered for 5 more minutes. Sprinkle the cheese over the top, then turn off the heat.
Cover again and rest until the cheese is melted. Top it off with your favorite toppings.
