Preheat your oven to 375°F (190°C).
In a small skillet, heat the olive oil over medium heat and sauté the diced white onion and minced garlic until softened and fragrant.
In a small bowl, whisk together the tomato puree, chili powder, ground cumin, sea salt, and black pepper to create the red chili sauce.
Place the cooked shredded chicken in a bowl and toss with two tablespoons of the prepared sauce to keep the filling moist.
Warm the corn tortillas slightly in a dry pan or microwave for 10 seconds to make them pliable and prevent cracking.
Spread a thin layer of sauce in the bottom of a small oven-safe baking dish.
Lay out each tortilla, fill with the chicken mixture and sautéed onions, then roll tightly and place seam-side down in the dish.
Pour the remaining red chili sauce over the top of the tortillas and sprinkle evenly with the shredded cheddar cheese.
Bake for 15 minutes until the sauce is bubbling and the cheese has melted into a golden crust.
Garnish with fresh cilantro and serve immediately.