Heat oil in large skillet on medium heat. Add chicken; cook and stir 3 to 5 minutes or until no longer pink.
Stir in in Seasoning Mix and water.
Bring to boil. Reduce heat to low; simmer 5 to 7 minutes or until most of liquid is absorbed, stirring occasionally. Spoon into warm taco shells. Serve with desired toppings.
Pork Tacos: Prepare as directed using 1 pound boneless pork chops, cut into 1/2-inch cubes or strips.