Preheat your oven to 375°F (190°C).
In a small mixing bowl, whisk together the tomato puree, chili powder, ground cumin, garlic powder, sea salt, and black pepper to create the enchilada sauce.
Heat the olive oil in a skillet over medium heat and sauté the diced red onion and red bell pepper until they are soft and fragrant.
Add the shredded cooked chicken to the skillet along with 2 tablespoons of the prepared enchilada sauce to keep the meat moist.
Warm the corn tortillas in a dry pan or microwave for 10 seconds to make them pliable, then fill each tortilla with the chicken and pepper mixture.
Roll the tortillas tightly and place them seam-side down in a small baking dish.
Pour the remaining red chili sauce over the tortillas and sprinkle evenly with the shredded sharp cheddar cheese.
Bake for 15 to 20 minutes until the cheese is melted and bubbly.
Remove from the oven and garnish with freshly chopped cilantro before serving.