Poach the chicken breast in simmering water for 12-15 minutes until fully cooked, then shred using two forks.
In a small saucepan, combine tomato puree, chicken broth, ancho chili powder, cumin, garlic powder, and onion powder over medium heat.
Simmer the sauce for 5 minutes until it thickens slightly, then season with sea salt and black pepper.
Warm the corn tortillas, dip each into the sauce to coat both sides, and fill with the shredded chicken.
Roll the tortillas tightly, place them seam-side down in a baking dish, pour over the remaining sauce, and bake at 375°F for 10 minutes.
Serve topped with sliced avocado, a dollop of Greek yogurt, fresh cilantro, and a squeeze of lime.