Preheat oven to 375°F and lightly grease a small baking dish.
In a small skillet, heat the olive oil over medium heat and sauté the red onion until translucent and fragrant.
In a small bowl, whisk together the tomato puree, chili powder, ground cumin, garlic powder, onion powder, sea salt, and black pepper to create the red chili sauce.
In a separate bowl, combine the shredded chicken breast with 2 tablespoons of the prepared sauce and the sautéed onions.
Warm the corn tortillas slightly in a dry pan or microwave to make them pliable, then fill each with the chicken mixture and roll tightly.
Place the rolled tortillas seam-side down in the baking dish, top with the remaining red chili sauce, and sprinkle with the shredded cheddar cheese.
Bake for 15 to 20 minutes until the sauce is bubbling and the cheese has melted into a golden crust.