Preheat your oven to 375°F (190°C).
In a small saucepan, combine the tomato puree, chili powder, cumin, garlic powder, sea salt, and black pepper. Simmer over low heat for 5 minutes to develop the flavors.
Heat the olive oil in a skillet over medium heat. Add the diced onion and red bell pepper, sautéing until softened and slightly caramelized.
In a mixing bowl, combine the cooked shredded chicken with the sautéed vegetables and 2 tablespoons of the prepared red chili sauce.
Warm the corn tortillas in a dry skillet for 30 seconds per side until pliable.
Spread 2 tablespoons of the chili sauce on the bottom of a small baking dish.
Place half of the chicken mixture into each tortilla, roll them tightly, and place them seam-side down in the baking dish.
Pour the remaining chili sauce over the tortillas and sprinkle with the shredded sharp cheddar cheese.
Bake for 15-20 minutes until the sauce is bubbling and the cheese is melted.
Garnish with freshly chopped cilantro before serving.