Pour water into the bottom of your slow cooker. Place chicken breasts in the slow cooker and sprinkle with grated onion, minced garlic, salt and pepper.
Turn your slow cooker on high heat for 3 1/2 hours or on low heat for 6 hours.
When the chicken is fork tender, easily shred chicken with two forks. You can also use a hand mixer and easily shred chicken with beater attachment. Enjoy!