In a large skillet over medium-high heat, heat the olive oil. Add the onion, garlic, and bell peppers. Sprinkle in salt and pepper and cook until softened, about 5-7 minutes.
Scoot the veggies to the side of the skillet and add the diced chicken to the empty side. Cook the chicken until it's browned on all sides, about 5 minutes.
Lower the heat to medium and add the corn, zucchini, black beans, tomatoes, and taco seasoning. Sprinkle in half of the chopped cilantro.
Let the mixture continue simmering, stirring occasionally, until the chicken is cooked through and everything is heated through, about 10 minutes.
Remove the skillet from the heat and sprinkle the shredded cheese evenly over the skillet. Once the cheese melts, sprinkle over the rest of the chopped cilantro.
Serve hot on its own or over rice.