1) In a large bowl, combine 2 cups water, brown sugar, soy sauce, orange juice concentrate, mustard, salt, pepper, ginger, and garlic salt.

2) Reserve half of marinade in another bowl; cover and refrigerate.

3) Place chicken and remaining marinade in a resealable plastic bag or glass dish.

4) Refrigerate chicken in marinade 8 hours or overnight.

5) Drain chicken; discard marinade from chicken.

6) Place chicken and reserved marinade in slow cooker.

7) Cover and cook on low for 7-8 hours.

8) Combine cornstarch and 1/2 cup cold water until smooth; stir into slow cooker.

9) Add oranges and green peppers.

10) Cover and cook on high for 30-45 minutes or until thickened.

11) Serve over hot rice.