Preheat the oven to 400°F (200°C).
Heat the olive oil in a large oven-safe skillet over high heat.
Add the ground chicken and chopped onion to the skillet; season with kosher salt and black pepper and cook, breaking up the meat, until browned, about 5 minutes.
Stir in the taco seasoning and cook 2 more minutes, then add 1/2 cup water, the salsa or enchilada sauce, and the chopped chipotle; simmer for 5 minutes.
Remove the skillet from the heat and stir in a small handful of chopped cilantro if desired.
In a medium bowl, combine the fresh corn, cream cheese, Greek yogurt, chili powder, and a pinch of salt until smooth; stir in 1/2 cup of the shredded cheese.
Dollop one-third of the corn mixture over the chicken in the skillet.
Scatter the tortilla chips over the corn mixture and press them gently into the skillet.
Spoon the remaining corn mixture over the chips in dollops, then sprinkle the remaining shredded cheese evenly on top.
Bake in the preheated oven until the cheese is melted and bubbly, about 15 minutes.
Serve topped with sliced avocado, additional cilantro, and sliced green onions.