Line chicken breasts in the bottom of the bowl of the slow cooker.
In a bowl combine a 1/2 cup of water with soy sauce, balsamic vinegar, sugar, garlic and Sriracha sauce
Pour mixture over chicken cook on low for 6 hours or high for 4 hours
At the end of the cooking time remove chicken from slow cooker and set aside on a plate. Add cornstarch and a table spoon of water to liquid in the slow cooker then stir to combine. Replace lid and turn crock pot to high. Cook for 15 minutes to allow sauce to thicken.
While sauce is cooking shred chicken. At the end of 15 minutes return chicken to slow cooker and stir to coat in sauce.
Serve over rice or noodles and garnish with sesame seeds and green onions.