Lightly salt and pepper the chicken – if using breast cut into even slices.
In a bowl, whisk together barbecue sauce, apple cider vinegar, brown sugar and water.
In a large skillet, melt butter and lightly brown the chicken.
Pour sauce over the chicken and bring to a simmer. Turn heat down to keep the sauce at just a simmer and cover. Cook for 5 minutes, flip the chicken breasts, and continue to cook, covered, until they are cooked through. If at any time the sauce begins to get too thick, add just a bit more water to the pan. This also works well in a slow cooker.
Transfer the chicken to a cutting board and let it rest for 5 to 10 minutes before shredding with two forks.
Return the shredded chicken to the sauce, toss to coat, and enjoy!