Preheat your oven to 375°F (190°C).
In a small skillet, heat the olive oil over medium heat and sauté the diced bell peppers and onions until they are soft and slightly caramelized.
In a mixing bowl, whisk together the Greek yogurt, red enchilada sauce, sea salt, black pepper, and garlic powder until smooth.
Place the cooked, shredded chicken breast in a separate bowl and toss with half of the creamy enchilada sauce and the sautéed vegetables.
Slice the corn tortilla into thin strips.
In a small oven-safe baking dish, layer half of the chicken mixture, followed by half of the tortilla strips.
Repeat the layer with the remaining chicken and tortillas, then pour the rest of the creamy sauce over the top.
Sprinkle with the shredded sharp cheddar cheese.
Bake for 15 to 20 minutes until the cheese is melted and the edges are bubbling.
Remove from the oven and garnish with fresh chopped cilantro before serving.