Place chicken in crockpot.
In a medium bowl combine brown sugar, soy sauce, vinegar, ginger, garlic and pepper.
Pour over chicken and cook on low heat 4-5 hours.
Remove chicken from slow cooker and chop into cubes. Set aside.
Transfer liquid from slow cooker to a skillet and bring to a boil.
Whisk together cornstarch and water.
Slowly add cornstarch mixture to boiling liquid and reduce to a simmer.
Allow sauce to thicken(about 2-3 minutes) then toss chicken back in the mix.
Coat chicken with sauce and let heat through.
Serve over rice with Stir-fry vegetables.