Preheat your oven to 375°F and line a baking sheet with foil. Pat the chicken dry with paper towels and rub with oil, salt, and pepper. Bake for about 30 minutes or until cooked through. (Internal temp. of 170℉, juices run clear)
In a large bowl, whisk together the water, taco seasoning, tomato sauce, vinegar, garlic, oregano, cumin, and sugar. Set aside.
When the chicken is done, let it rest for 10 minutes and then shred it with two forks. Transfer it to a large skillet over medium-high heat and pour the sauce over it. Stir well to coat and simmer until slightly thickened, about 5-10 minutes.
Warm up your taco shells or tortillas in the microwave or oven according to the package directions. Spoon some chicken and sauce onto each shell or tortilla and top with your favorite toppings. Enjoy!
Your choice of toppings (such as cheese, lettuce, tomato, onion, cilantro, sour cream, salsa, etc.)
Serve with tortilla chips, or nachos, and refried or black beans, and maybe some elote (Mexican style corn on the cob), and Mexican rice.