Put the chicken breasts in the bottom of your slow cooker and sprinkle with salt and pepper.

Chop up half of a small yellow onion and set it aside.

In a small bowl, mix together chicken stock, balsamic vinegar, the chopped onion, minced garlic, and brown sugar.

Pour that mixture over the chicken, making sure it’s all coated.

Set your slow cooker to low and let it cook for 8 hours.

When it’s done, shred the chicken right in the slow cooker with two forks. Stir it into the sauce so it soaks up all the flavor.