Preheat your oven to 375°F (190°C).
In a small saucepan, whisk together the tomato puree, ancho chili powder, garlic powder, onion powder, sea salt, and black pepper over medium heat until it reaches a simmer.
Heat the avocado oil in a skillet over medium-high heat and sauté the diced bell peppers and white onion until they are tender and slightly charred.
In a medium bowl, combine the sautéed vegetables with the cooked, shredded chicken breast.
Lightly warm the corn tortillas, then dip each one into the warm ancho sauce to coat both sides.
Fill each tortilla with the chicken and pepper mixture, roll them up tightly, and place them seam-side down in a small baking dish.
Pour the remaining sauce over the top of the tortillas and sprinkle with the shredded cheddar cheese.
Bake for 15 minutes until the cheese is melted and bubbly and the edges of the tortillas are slightly crisp.
Garnish with fresh chopped cilantro before serving warm.