Preheat the oven to 430°F (220°C). Arrange racks in the upper and lower thirds of the oven.
Heat the oil in a skillet over medium-high heat. Add the cooked chicken and cook for 2 to 3 minutes until lightly golden.
Place the flatbreads on two baking sheets.
Spread the enchilada sauce evenly over each flatbread, leaving a small border around the edge.
Divide the chicken, corn, bell pepper, and red onion over the flatbreads.
Sprinkle mozzarella cheese evenly over the toppings.
Bake for 8 to 12 minutes, rotating the trays halfway through, until the cheese is melted and bubbling.
Garnish with cilantro or parsley, slice into wedges, and serve hot.