In a bowl mix the egg with the milk.

In another bowl, mix the flour and panko together. In 5-10 piece batches, soak chicken chunks in milk mixture then roll in flour mixture, then dip in milk again, then roll in the flour mixture. Do this until all the chicken is coated. This builds up a nice coating on the chicken.

In a large skillet, heat the olive oil and brown your chicken on all sides. You will not be fully cooking the chicken, just giving it a nice brown color. Place the chicken pieces into your slow cooker.

In another small bowl, mix together the orange juice, brown sugar, vinegar, salt, and ketchup, add more sugar if you want a sweeter taste. Pour the sauce over the chicken and carefully toss to coat the chicken pieces.

Cover and cook on Low setting for 6 hours or High setting for 3 hours. Serve over steamed rice.