Preheat your oven to 375°F (190°C).

Boil sweet potatoes in a large pot for about 10 minutes until tender. Drain and set aside.

Heat olive oil in a skillet over medium heat, sauté red onion and bell pepper for 5 minutes until soft. Add minced garlic and sauté for another minute.

In a mixing bowl, combine cooked sweet potatoes, black beans, corn, and sautéed vegetables. Add spices, lime juice, salt, and pepper. Mix well.

Layer half of the mixture in a greased 9x13-inch baking dish, top with half the cheese. Repeat with remaining mixture and cheese.

Pour vegetable broth around the edges of the casserole, cover with foil, and bake for 30 minutes. Remove foil and bake for an additional 15 minutes.

Let the casserole cool for a few minutes, garnish with cilantro if desired, and serve warm.