Preheat your oven to 375°F (190°C) and lightly grease a small baking dish.
Heat the olive oil in a skillet over medium heat, then add the chicken breast, diced bell peppers, and onions.
Cook until the chicken is golden and cooked through, then remove from heat and shred the chicken using two forks.
In a small bowl, toss the shredded chicken and sautéed vegetables with the chili powder, cumin, sea salt, and black pepper.
In a separate bowl, whisk together the plain Greek yogurt and red enchilada sauce until smooth and creamy.
Spread two tablespoons of the sauce on the bottom of the baking dish.
Warm the corn tortillas slightly to prevent cracking, then dip each one into the sauce to coat.
Fill each tortilla with the chicken mixture, roll tightly, and place seam-side down in the baking dish.
Pour the remaining sauce over the top and sprinkle with the shredded sharp cheddar cheese.
Bake for 15-20 minutes until the sauce is bubbling and the cheese is melted and slightly golden.