Heat a large skillet over medium heat.Add the diced onion and cook for 3–4 minutes until softened. Add the ground chicken, breaking it apart as it cooks.Cook until the chicken is no longer pink and fully cooked through. Sprinkle in the taco seasoning and pour in the water.
Stir well until every piece of chicken is coated in the seasoning.Let the mixture simmer for about 5 minutes until the liquid reduces and the filling becomes flavorful.Remove from heat Warm the tortillas for about 20–30 seconds so they're soft and easy to roll.(This helps prevent them from cracking while rolling.)
Lay a tortilla flat. Add a spoonful of the seasoned chicken.Top generously with shredded Oaxaca cheese.Roll tightly and place seam-side down.
Heat about 1 inch of oil in a skillet over medium heat.Once hot, carefully place the rolled tacos seam-side down first.Cook for 2–3 minutes per side until beautifully golden brown and crispy.Transfer to a wire rack or paper towel-lined plate. Pile them onto a serving platter and serve immediately with your favorite toppings and plenty of salsa for dipping.They're delicious with Mexican rice, refried beans, chips, or a fresh salad.