Mix egg and milk in a small bowl.
In a separate bowl, mix your flour and panko. In 5-10 piece batches, soak chicken chunks in milk mixture then in flour mixture, Repeat this twice.
In a large skillet, heat olive oil on the stove and brown your chicken on all sides. You will not be fully cooking the chicken, just giving it a nice coat. Place the chicken pieces into your slow cooker
In a small mixing bowl, combine orange juice concentrate, brown sugar, balsamic vinegar, salt, and ketchup. Add more sugar if you prefer a sweeter taste. Pour sauce evenly over the chicken, and carefully toss to coat.
Cover and cook on low for 6 hours, or on high for 3 to 4. Serve warm over the rice or noodles of your choice.