Preheat your oven to 375°F (190°C) and lightly grease a small baking dish with a drop of avocado oil.
In a skillet over medium heat, sauté the diced red bell pepper and yellow onion in avocado oil until softened and slightly caramelized.
In a medium bowl, combine the cooked shredded chicken breast, sautéed vegetables, lime juice, garlic powder, sea salt, and black pepper.
In a separate small bowl, whisk together the Greek yogurt, tomato puree, and minced chipotle peppers until a smooth, creamy sauce forms.
Spread a thin layer of the chipotle sauce on the bottom of the baking dish to prevent sticking.
Warm the corn tortillas slightly to make them pliable, then fill each with the chicken mixture, roll tightly, and place seam-side down in the dish.
Pour the remaining creamy chipotle sauce over the tortillas and sprinkle evenly with the shredded cheddar cheese.
Bake for 15 to 20 minutes until the sauce is bubbling and the cheese has melted into a golden crust.
Garnish with fresh chopped cilantro before serving.