Preheat your oven to 375°F (190°C).
In a small saucepan over medium heat, combine the tomato puree, chili powder, ground cumin, garlic powder, and onion powder to create the red chili sauce.
Simmer the sauce for 5 minutes, then season with sea salt and black pepper.
Heat the olive oil in a skillet and sauté the diced white onion and green bell pepper until they are softened and fragrant.
Stir the cooked shredded chicken breast into the skillet with the vegetables and add 2 tablespoons of the prepared sauce to moisten the mixture.
Warm the corn tortillas briefly in a dry pan or microwave to make them pliable for rolling.
Place a portion of the chicken and vegetable mixture into each tortilla, roll tightly, and place them seam-side down in a small baking dish.
Pour the remaining red chili sauce evenly over the tortillas and sprinkle with the shredded sharp cheddar cheese.
Bake for 15-20 minutes until the sauce is bubbling and the cheese has completely melted.
Garnish with freshly chopped cilantro before serving.