Preheat your oven to 375°F (190°C).
Heat the olive oil in a skillet over medium heat and sauté the diced bell pepper and onion until they are soft and translucent.
In a large mixing bowl, combine the cooked shredded chicken breast, Greek yogurt, green enchilada sauce, cumin, garlic powder, sea salt, and black pepper.
Fold the sautéed vegetables into the chicken mixture until everything is evenly coated in the creamy sauce.
Slice the corn tortillas into one-inch strips or bite-sized quarters.
Lightly grease a small oven-safe baking dish and spread a thin layer of the chicken mixture on the bottom.
Create a layer using half of the tortilla pieces, then top with half of the remaining chicken mixture.
Repeat with the rest of the tortillas and the final layer of chicken mixture.
Sprinkle the shredded cheddar cheese evenly over the top of the dish.
Bake for 20 minutes, or until the edges are golden and the cheese is melted and bubbly.