Preheat your oven to 375°F and lightly grease a small oven-safe baking dish with the olive oil.
In a medium mixing bowl, whisk together the Greek yogurt, tomato puree, diced green chilis, sea salt, black pepper, chili powder, and garlic powder until smooth.
Add the cooked, shredded chicken breast to the bowl and toss until every piece is thoroughly coated in the creamy chili sauce.
Slice the corn tortilla into thin strips or small bite-sized squares.
Place half of the tortilla pieces in the bottom of the prepared baking dish, followed by the chicken mixture, and then the remaining tortilla pieces.
Sprinkle the shredded cheddar cheese evenly over the top of the dish.
Bake for 18 to 20 minutes until the cheese is melted and golden and the sauce is bubbling around the edges.