Preheat your oven to 375°F.
Heat the avocado oil in a skillet over medium heat and sauté the diced bell peppers and red onion until they are just softened, about 5 minutes.
Season the chicken breast with sea salt and black pepper, then pan-sear or poach until cooked through; once cooled slightly, shred the meat using two forks.
Slice the corn tortilla into thin, uniform strips.
In a small oven-safe baking dish, spread a thin layer of the red enchilada sauce across the bottom.
Layer half of the corn tortilla strips over the sauce, followed by half of the shredded chicken and half of the sautéed vegetables.
Drizzle half of the remaining enchilada sauce over the layer and repeat the process with the remaining tortillas, chicken, and vegetables.
Pour the final bit of sauce over the top and sprinkle the shredded cheddar cheese evenly across the surface.
Place the dish in the oven and bake for 15-20 minutes until the sauce is bubbling and the cheese has melted into a golden crust.
Garnish with fresh cilantro before serving hot.