Preheat your oven to 375°F (190°C) and lightly grease a small baking dish.
Heat the olive oil in a skillet over medium heat and cook the chicken breast until fully opaque, then shred it thoroughly using two forks.
In a small saucepan, whisk together the tomato puree, chicken broth, chili powder, cumin, garlic powder, onion powder, sea salt, and black pepper.
Bring the sauce to a gentle simmer for 5 minutes until the flavors meld and the liquid thickens slightly.
Warm the corn tortillas in a dry pan for 30 seconds per side until they are soft and pliable.
Dip each tortilla into the red chili sauce to coat, then fill with the shredded chicken and roll tightly.
Arrange the enchiladas seam-side down in the baking dish and pour the remaining sauce over the top.
Top with the shredded sharp cheddar cheese and bake for 15 minutes until the cheese is melted and the sauce is bubbling.