In a large pot, heat the olive oil over medium heat. Add the diced onion and cook until softened, about 5 minutes. Stir in the minced garlic and diced bell pepper, cooking for an additional 2-3 minutes until fragrant.

Add the ground cumin, chili powder, and smoked paprika to the pot, stirring well to combine. Cook for another minute to toast the spices.

Stir in the black beans, corn, diced tomatoes, and vegetable broth. Bring the mixture to a boil, then reduce the heat and let it simmer for 10 minutes.

In a separate bowl, whisk together the masa harina and water until smooth. Slowly add this mixture to the soup, stirring constantly to prevent lumps. Continue to simmer for another 5-10 minutes, until the soup thickens slightly.

Season with salt and pepper to taste. Serve hot, topped with shredded cheese, fresh cilantro, and lime wedges.