1. While the onion and grapes are baking, prepare your schnitzel. Set up two bowls: in the first, use a fork to beat the egg. In the second bowl combine panko, ground walnuts, salt, and garlic powder. Dip each chicken piece into the egg and then into the panko mixture.
2. Once all the chicken pieces are breaded, heat a large non-stick pan over medium heat with enough vegetable oil to cover the bottom of the pan. Once the oil is hot, fry each piece of chicken for about three to four minutes per side, or until both sides are crispy and a deep shade of brown. Do not overcrowd the pan, as this will create steam and will prevent the chicken from crisping up. Place finished chicken on a cooling rack or a paper towel-lined plate.