Preheat your oven to 375°F.
In a small saucepan, whisk together the tomato puree, ancho chili powder, cumin, garlic powder, sea salt, and black pepper over medium heat until warmed through.
Heat the avocado oil in a skillet and sauté the diced bell peppers and onions until they are softened and fragrant.
Toss the cooked shredded chicken with 2 tablespoons of the prepared ancho sauce and the sautéed vegetables.
Briefly warm the corn tortillas in a dry pan over medium heat for 30 seconds per side to make them pliable.
Fill each tortilla with the chicken and vegetable mixture, roll them tightly, and place them seam-side down in a small baking dish.
Pour the remaining ancho sauce evenly over the tortillas and sprinkle with the shredded cheddar cheese.
Bake for 15 minutes until the sauce is bubbling and the cheese has melted completely.
Garnish with chopped fresh cilantro before serving.