Crock Pot Sweet Garlic Chicken

4-6 chicken breasts
1 cup packed brown sugar
2/3 cup vinegar (I used apple cider vinegar)
1/4 cup water
2t lemon juice
2-3 Tablespoons minced garlic
2 Tablespoons soy sauce
1 teaspoon fresh ground pepper
2 Tablespoons corn starch
2 Tablespoons water
Red pepper flakes (optional)

Cook in crock pot on low 6-8 hours