In a large skillet, heat the olive oil over medium heat. Add the diced onion and cook for about 3-4 minutes until softened.
Add the minced garlic and diced bell pepper to the skillet. Cook for an additional 3-4 minutes until the bell pepper is tender.
Increase the heat to medium-high and add the ground turkey. Cook, breaking it apart with a spatula, until browned and cooked through, about 5-7 minutes.
Stir in the black beans, diced tomatoes (with juices), taco seasoning, cumin, salt, and pepper. Bring to a simmer and cook for 5 minutes, allowing the flavors to meld.
Add the corn and stir to combine. Cook for another 2-3 minutes until heated through.
Sprinkle the shredded cheddar cheese on top and cover the skillet. Let it sit for 2-3 minutes until the cheese is melted.
Garnish with fresh cilantro and serve with sour cream and tortilla chips if desired.