Preheat your oven to 375°F and lightly grease a small oven-safe baking dish.
Finely dice the bell pepper and yellow onion into uniform pieces.
Heat the olive oil in a skillet over medium heat and sauté the peppers and onions until they are soft and translucent.
Add the chicken breast to the skillet and season with sea salt, black pepper, garlic powder, and ground cumin.
Cook the chicken until no longer pink, then remove from the pan and shred it into small pieces using two forks.
In a separate small bowl, whisk together the red enchilada sauce and plain Greek yogurt until the mixture is smooth and creamy.
Slice the corn tortilla into half-inch wide strips.
Layer the shredded chicken, sautéed vegetables, and half of the creamy sauce into the prepared baking dish.
Top the mixture with the tortilla strips, the remaining sauce, and the shredded cheddar cheese.
Bake for 15 to 20 minutes until the sauce is hot and the cheese has reached a bubbly, golden state.