Preheat your oven to 375°F (190°C).
In a small saucepan, whisk together the tomato puree, chili powder, cumin, sea salt, and black pepper over medium heat to create a smooth red chili sauce.
Heat the olive oil in a skillet over medium heat and sauté the diced white onion and bell pepper until softened, then add the minced garlic for 30 seconds.
Add the cooked shredded chicken to the skillet and toss with 2 tablespoons of the prepared red chili sauce to coat.
Warm the corn tortillas in a dry pan for 10 seconds per side until they are soft and pliable.
Fill each tortilla with half of the chicken and pepper mixture, roll them tightly, and place them seam-side down in a small baking dish.
Pour the remaining red chili sauce evenly over the top of the enchiladas.
Bake for 15 minutes until the sauce is bubbling and the tortillas are slightly toasted.
Garnish with a dollop of nonfat Greek yogurt and fresh cilantro before serving.