Preheat your oven to 375°F (190°C).
Heat the olive oil in a skillet over medium heat and sauté the diced onion and red bell pepper until softened.
Add the shredded cooked chicken breast to the skillet, seasoning with sea salt and black pepper, and stir until combined.
In a small mixing bowl, whisk together the tomato puree, chili powder, ground cumin, and garlic powder to create the red chili sauce.
Lightly warm the corn tortillas in a dry pan or microwave for 10 seconds to make them pliable.
Spread a spoonful of the sauce onto each tortilla, add the chicken and pepper mixture, and roll them up tightly.
Place the rolled tortillas seam-side down in a small baking dish.
Pour the remaining red chili sauce over the top of the tortillas, ensuring they are well-covered.
Sprinkle the shredded cheddar cheese evenly over the sauce.
Bake for 15 minutes, or until the cheese is melted and the sauce is bubbling around the edges.